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LT3782EFE#PBF - 2-Phase 500kHz Boost Controller | ADI | 28-TSSOP-EP
The Analog Devices LT3782EFE#PBF is a current-mode, two-phase step-up (boost) DC/DC converter controller housed in a 28-pin TSSOP-EP (HTSSOP) package with exposed thermal pad. It operates from 6V to 40V input, supports switching frequencies up to 500 kHz, and delivers 4 A peak gate-drive current with 10 V gate drive (when Vcc ≥ 13 V), enabling efficient driving of industrial-grade high-power MOSFETs. A boost (step-up) DC/DC controller is a type of switching voltage regulator that produces an output voltage higher than its input voltage by storing energy in an inductor and releasing it into the output capacitor through a power switch. Two-phase interleaved operation, as implemented in the LT3782, runs two boost phases 180° out of phase, which halves the input/output ripple current amplitude and doubles the effective ripple frequency. The result is smaller magnetics, lower EMI, and reduced filter capacitance versus a single-phase equivalent. Within the broader taxonomy: boost controller -> DC/DC switching controller -> power management IC -> semiconductor. Key features include 6 V to 40 V input range (Vcc start-up as low as 6 V with operation down to 4 V after start), adaptive or programmable current-mode control, internal 4 A gate drivers for both top and bottom MOSFETs in each phase, programmable switching frequency up to 500 kHz, and synchronizable to an external clock. The TSSOP-28 EP package offers thermal resistance θJA near 28 °C/W on a standard JEDEC 4-layer board, supporting the high-power dissipation expected of a 2-phase high-current boost stage. The 2-phase architecture also benefits high-current applications because it spreads power dissipation across two inductors and two MOSFET pairs, reducing per-component thermal stress. Synchronous rectification is supported by the bottom-gate driver output on each phase, allowing use of low-Rds(on) N-channel MOSFETs for high-efficiency conversion. Programmable soft-start, current limit, and synchronization round out the feature set. Typical applications include 12 V/24 V to 48 V industrial bus converters, automotive 12 V step-up pre-regulators for audio amplifiers, telecom hold-up converters, and any high-current (>10 A) boost topology where input ripple and EMI must be minimized. The LT3782 is well suited to systems where two single-phase converters would otherwise be paralleled. Designers should size the two inductors with a 180° phase relationship, use low-ESR ceramic or polymer output capacitors, and connect the exposed pad (EP) to a large copper pour to manage MOSFET-driving losses. For very high output currents, sync-MOSFETs and Schottky rectifiers should be selected to minimize conduction loss. This page consolidates distributor pricing, verified drop-in alternatives, and engineering design notes that go beyond the ADI datasheet's typical application section.
LT3782EFE#TRPBF - 2-Phase Boost DC/DC Controller, 500kHz | ADI
The Analog Devices LT3782EFE#TRPBF is a current-mode 2-phase step-up DC/DC converter controller housed in a 28-pin TSSOP-EP (TSSOP-28 with exposed pad) package. Its high switching frequency up to 500 kHz and 2-phase architecture reduce required input/output filtering capacitance and inductance. The device delivers 10 V gate drive (VCC >= 13 V) with 4 A peak gate-drive current to drive industrial-grade high-power MOSFETs efficiently. Operating input range covers 6 V to 40 V, making the controller suited to 12 V, 24 V, and 40 V industrial bus rails. A two-phase boost controller is a current-mode switching regulator that interleaves two converter phases 180 degrees out of phase. This interleaving halves the input ripple current and doubles the effective switching frequency seen by the input filter, allowing the use of smaller magnetics and capacitors. The controller sits in the broader hierarchy of DC/DC converters -> switching regulators -> power management ICs -> semiconductors, and is the high-power counterpart to single-phase boost controllers when output currents exceed what a single phase can comfortably supply. Key features include programmable switching frequency, selectable two-phase or single-phase operation, synchronizable oscillator, soft-start, and adaptive dead-time control for synchronous MOSFET applications. The 4 A peak gate-drive capability supports high-Ciss MOSFETs without external gate drivers, while the 10 V gate drive is compatible with standard threshold N-channel power MOSFETs. The TSSOP-EP package provides a thermal pad for improved heat dissipation and reliable operation at high switching currents. The 2-phase topology reduces input RMS current by approximately 50% compared with single-phase equivalents at the same load, decreasing input capacitor stress and EMI. Adaptive dead-time control prevents cross-conduction in synchronous rectifier configurations. The internal soft-start and current-mode control simplify loop compensation and enable reliable step-up conversion from wide-input sources to high-output voltages required by industrial, automotive, and telecom systems. Typical applications include high-power LED drivers, industrial 24 V to high-voltage DC bus conversion, automotive audio amplifier supplies, telecom -48V hold-up converters, and high-voltage bias generators for LCD backlights. The wide 6V-40V input tolerates load-dump and transients commonly encountered in industrial and automotive environments. When designing with this device, ensure the exposed pad is soldered to a sufficiently large copper pour for thermal dissipation. Select the inductor and input capacitor based on the desynchronized ripple current of each phase. Use proper PCB layout to minimize switching-node area and reduce EMI.
LT3790EFE - 60V 4-Switch Sync Buck-Boost Controller | ADI
The Analog Devices LT3790EFE is a 60V synchronous 4-switch buck-boost controller that regulates output voltage, output current, or input current with input voltages above, below, or equal to the output voltage, packaged in a 38-lead TSSOP with an exposed thermal pad. It accepts a wide 4.7V to 60V input range, supports an adjustable output of 1.2V to 60V, and delivers up to 10A of output current with up to 98.5% efficiency through its constant-frequency current-mode architecture. A buck-boost controller is a DC-DC switching converter topology that uses a single inductor and four switches to step the input voltage up or down (or pass it through) while maintaining a regulated output. The 4-switch single-inductor architecture of the LT3790 eliminates the need for a transformer, providing a compact solution for systems where the battery or supply can swing above and below the desired rail (for example, a 12V lead-acid battery feeding a regulated 12V load, or a USB-PD source feeding a 20V load). Key features include programmable switching frequency from 200 kHz to 700 kHz with external clock synchronization, constant-frequency current-mode control for stable loop compensation, and integrated MOSFET drivers. Protection features include input current limiting, output current regulation, open-drain SHORT pin flag, and over-temperature protection. Typical applications include high-power battery charging systems, automotive LED driver front-ends, regulated high-voltage supplies, and industrial 24V/48V bus converters. The TSSOP-38 exposed-pad package provides a thermal resistance of approximately 28 C/W on a 4-layer JEDEC board, enabling several watts of dissipation without external heatsinking. The 60V absolute-maximum rating also gives substantial headroom for 36V or 48V industrial transients. Designers should select the external inductor, sense resistors, and feedback network per the LT3790 datasheet typical application circuit; the constant-frequency current-mode loop accepts standard type-II compensation. Use the SHORT pin as a power-good or fault flag in supervisory logic. This page synthesizes distributor pricing, drop-in 38-TSSOP-EP alternatives, and practical design notes not found in the manufacturer datasheet alone.
LT3790EFE#PBF - 60V Sync 4-Switch Buck-Boost Controller | ADI
The Analog Devices LT3790EFE#PBF is a synchronous 4-switch buck-boost voltage/current regulator controller housed in a 38-pin TSSOP with exposed pad (TSSOP-38 EP). It regulates output voltage, output current, or input current with input voltages above, below, or equal to the output voltage, supporting input range of 4.7 V to 60 V and adjustable output of 1.2 V to 60 V with up to 10 A output current capability. A buck-boost converter is a switched-mode DC-DC topology that seamlessly transitions between buck (step-down) and boost (step-up) operation, maintaining a regulated output even when the input voltage crosses the output voltage. Buck-boost controllers sit within the broader hierarchy of DC-DC converters -> switching regulators -> power management ICs -> semiconductors. They are preferred over two-stage cascaded solutions when VIN can dip below or rise above VOUT, eliminating the need for separate boost and buck stages and improving efficiency. Key features of the LT3790 include 4-switch synchronous rectification for high efficiency, constant-frequency current-mode architecture, programmable switching frequency, and a status flag (SHORT) that asserts when the FB pin drops below 400 mV with VSENSE above 5 mV. The wide 4.7 V to 60 V input range supports automotive load-dump transients, 24 V industrial buses, and high-cell-count battery packs. Output disconnect is inherent in the topology, preventing DC current flow when VOUT is shorted to ground. The LT3790 uses peak current-mode control with a precision reference and adaptive shoot-through protection on the four N-channel MOSFET drivers. Its 200 kHz to 700 kHz programmable frequency (200 kHz default) allows designers to trade efficiency versus external inductor and capacitor size. Internal ±2% reference accuracy and cycle-by-cycle current limiting simplify compliance with AEC-Q100 and similar noise/ripple requirements. Typical applications include high-power LED drivers, battery charging systems for 12 V/24 V/48 V packs, USB Power Delivery (PD) and other wide-range input converters, solar charge controllers, and automotive infotainment/lighting rails. The 4-switch topology also makes it suitable for industrial telematics and robotics power where the input bus can vary widely. When designing with the LT3790, select four N-channel MOSFETs with adequate drain-source breakdown for the maximum VIN plus ringing margin, and use a low-ESR ceramic or polymer output capacitor bank sized to meet the dynamic load step requirement. The exposed pad must be soldered to a sufficiently large copper pour to keep junction temperature within the -40 C to +125 C operating range. This page synthesizes distributor pricing, same-family and cross-brand drop-in alternatives, and practical PCB/thermal design notes not found in the manufacturer datasheet alone.
LT3790EFE#TRPBF - 60V Sync 4-Switch Buck-Boost Controller | ADI
The Analog Devices LT3790EFE#TRPBF is a synchronous 4-switch buck-boost voltage and current regulator controller housed in a 38-pin TSSOP-EP exposed-pad package. It operates from 4.7V to 60V input, supports output voltages from 1.2V to 60V, and uses constant-frequency current-mode architecture adjustable from 200kHz to 700kHz. The device regulates output voltage, output current, or input current with input voltages above, below, or equal to the output voltage, eliminating top-FET refresh switching noise. A buck-boost controller is a type of DC-DC switching regulator that maintains a regulated output whether the input rail sits above, below, or equal to the output rail. The four-switch (H-bridge) topology combines a synchronous buck and a synchronous boost, transferring seamlessly across all three operating modes. Within the broader power management hierarchy, the LT3790 sits between buck-only or boost-only regulators and full-bridge converters, offering single-IC flexibility for systems with wide VIN variation. Key features include 60V absolute maximum input, 200kHz-700kHz programmable/synchronizable switching frequency, current-mode control with cycle-by-cycle current limiting, adjustable soft-start, input current limiting, output current limiting, and a built-in topology switchover that eliminates the third-quadrant refresh pulse typical of competing solutions. The exposed thermal pad supports high-power dissipation up to several watts, enabling compact industrial designs. The LT3790 uses a proprietary architecture that avoids the top-FET refresh switching common in 4-switch controllers, reducing switching losses and EMI while improving efficiency at light load. The constant-frequency current-mode control simplifies loop compensation and enables parallel operation for higher output current. Typical applications include automotive 12V/24V battery systems, industrial 24V/48V bus converters, battery-powered systems with wide VIN range, solar power conditioning, and high-power LED drivers. The wide input range and 60V absolute maximum also make it suitable for telecom 48V rails. When designing with this device, select MOSFETs with adequate VDS margin (80V or 100V for a 60V system) and use the exposed pad with sufficient copper for thermal dissipation. The efficiency at high VIN depends heavily on MOSFET RDS(ON) and gate charge selection. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, providing a one-stop engineering reference for LT3790EFE#TRPBF selection.
LT3791EFE#PBF - 60V 4-Switch Sync Buck-Boost LED Driver | ADI
The LT3791EFE#PBF from Analog Devices is a synchronous 4-switch buck-boost LED driver controller capable of regulating LED current up to 52V with input voltages above, below, or equal to the output voltage. Housed in a 38-pin TSSOP-EP package, this controller supports a wide input voltage range and delivers high efficiency up to 98.5%. A buck-boost LED driver controller is a power management IC that regulates current through an LED string by controlling four external MOSFETs in a single-inductor topology. It can step up or step down the input voltage to maintain a constant LED current, making it essential for applications where the supply voltage varies around the LED forward voltage. This controller sits within the hierarchy of LED drivers, which are part of power management integrated circuits used in lighting systems. Key features include a 4-switch single-inductor architecture that allows VIN above, below, or equal to VOUT, synchronous switching for efficiency up to 98.5%, a wide input voltage range, and 2% output voltage accuracy. The controller supports both analog and PWM dimming, with a frequency adjustable or synchronizable from 200kHz to 700kHz. It also provides open LED and short LED protection, along with a precision current sense amplifier. The LT3791EFE#PBF uses a constant-frequency, current-mode architecture with forced-continuous operation, ensuring stable operation across all conditions. The 4-switch topology eliminates the need for a separate boost and buck stage, reducing component count and board space. The controller can regulate LED current with ±2% accuracy, and its wide input range makes it suitable for automotive, industrial, and general lighting applications. Typical applications include automotive headlamps, industrial lighting, and high-power LED drivers. The device is ideal for battery-powered systems where input voltage varies, such as in vehicles or portable equipment. Its ability to operate with input voltages above or below the LED string voltage makes it versatile for various LED configurations. When designing with this controller, ensure proper PCB layout for the high-current switching paths and adequate thermal management for the external MOSFETs. The frequency synchronization pin allows multiple controllers to operate at the same frequency, reducing EMI in multi-channel designs.
LT3791EFE#TRPBF - 60V 4-Switch Sync Buck-Boost LED Driver | ADI
The LT3791EFE#TRPBF from Analog Devices is a synchronous 4-switch buck-boost LED driver controller designed to regulate LED current up to 52V with input voltages above, below, or equal to the output voltage. Housed in a 38-pin TSSOP-EP package, this controller supports constant-frequency, forced-continuous current mode operation, enabling efficient and accurate LED current regulation across a wide input range. A buck-boost LED driver controller is a specialized power management IC that combines step-down (buck) and step-up (boost) topologies to maintain a regulated output current regardless of whether the input voltage is higher or lower than the LED string voltage. This makes it ideal for automotive, industrial, and general lighting applications where input voltage variations are common. The LT3791 belongs to the family of switching regulators, specifically DC-DC controllers, which are essential in power management systems for converting and regulating electrical power efficiently. Key features include a wide 4.7V to 60V input voltage range, adjustable switching frequency from 200kHz to 700kHz, and the ability to synchronize to an external clock. The controller provides analog and PWM dimming, with PWM dimming capable of achieving high contrast ratios. Its 4-switch architecture allows seamless transitions between buck, boost, and buck-boost modes, ensuring stable operation across the entire input range. The device also includes features such as open LED protection, short-circuit protection, and a precision current sense amplifier. Technically, the LT3791 uses a current mode control architecture with a 4-switch synchronous topology, which improves efficiency by eliminating the need for external Schottky diodes. The controller can drive external N-channel MOSFETs, allowing designers to scale the solution to high-power applications. The forced-continuous current mode ensures predictable operation and simplifies EMI filtering. The device operates over a -40°C to 125°C junction temperature range, making it suitable for harsh environments. Typical applications include automotive LED lighting (headlights, daytime running lights), industrial lighting, and general-purpose constant-current LED drivers. Its wide input range and high output voltage capability make it particularly well-suited for LED strings in series, where the total forward voltage can be significant. When designing with the LT3791, careful attention must be paid to the switching node layout and the selection of external components, such as inductors and MOSFETs, to ensure stable operation and meet EMI requirements. The datasheet provides detailed application circuits and component selection guidelines.
LT3950EMSE - 60V 1.5A LED Driver w/ Exponential Dim | ADI
The Analog Devices LT3950EMSE is a 60 V, 1.5 A constant-current/voltage LED driver IC with internal exponential scale PWM dimming, housed in a 16-pin MSOP-EP package with an exposed thermal pad. It integrates a 1.5 A, 60 V internal DMOS power switch, supports multitopology operation (boost, buck, SEPIC, buck-boost, flyback, Ćuk), and runs at a fixed 2 MHz switching frequency that allows small ceramic input and output capacitors. The integrated PWM generator maps an analog control voltage (CTRL pin) to an exponential dimming profile, mimicking the human eye's logarithmic response to light intensity. A DC/DC LED driver is a switch-mode power supply specifically engineered to regulate current through a string of high-brightness LEDs rather than regulate output voltage. Within the broader power management IC hierarchy, the LT3950EMSE sits between general-purpose DC-DC converters (LM2591, LMR33640) and lighting-specific drivers (LM3405, LP5024). By combining the inductor-based switching converter and a constant-current regulation loop in one IC, the part eliminates the discrete sense resistor, op-amp, and MOSFET network that a discrete solution would otherwise require, simplifying BOMs in solid-state lighting designs. Key features include a wide 3 V to 60 V input range, 1.5 A internal switch rating, 200 mV current sense voltage (reducing conduction loss), open-drain fault indicator, programmable soft-start, and an auxiliary PWM input pin for synchronizing the LED brightness to an external MCU. The 2 MHz switching frequency stays above the AM band, while the internal exponential dimming generator removes the need for firmware-based gamma correction. Quiescent current is typically under 1 mA in shutdown. The LT3950EMSE uses a constant-frequency peak-current-mode control architecture. The internal high-side DMOS switch and current sense amplifier form the inner current loop, while an external resistor on the SENSE pin programs the LED current setpoint. The exposed pad (EP) of the MSOP-16 provides a low-thermal-resistance path (θJA ≈ 38 °C/W on a 4-layer JEDEC JESD51-7 board) so 1.5 A operation is feasible without an external heatsink for moderate VIN-VOUT differentials. Typical applications include automotive daytime running lights, architectural and signage lighting, MR16 and AR111 LED retrofit lamps, constant-current LED strings, and backlight drivers for industrial displays. Its 60 V rating also makes it suitable for 36 V industrial bus rails or 48 V telecom supply chains. When designing with this part, pay attention to inductor saturation current (must exceed 2 A), input bulk capacitance for hot-plug events, and PCB thermal copper under the exposed pad. A common pitfall is leaving the exposed pad unsoldered, which can raise junction temperature by 20-30 °C and trigger thermal shutdown at 1.5 A. This page synthesizes distributor pricing, drop-in alternatives, application notes, and design guidance not consolidated in any single vendor listing, helping engineers select and source the LT3950EMSE faster.
LT3971EMSE - 38V, 1.2A, 2MHz Buck Regulator | Analog Devices
The Analog Devices LT3971EMSE is an adjustable-frequency monolithic buck switching regulator that accepts a wide input voltage range up to 38V and delivers up to 1.2A of output current in a 10-lead MSOP-10 (MSE) package with an exposed pad for low thermal resistance. Key headline parameters: 38V maximum input voltage, 1.2A continuous output current, and 2.8µA quiescent current with Burst Mode operation. The switching frequency is user-programmable from 200kHz to 2MHz, allowing optimization between efficiency and external component size. What is a buck switching regulator? A buck (step-down) switching regulator is a type of DC-DC converter that efficiently reduces a higher input voltage to a lower regulated output voltage by rapidly switching an inductor and using energy storage elements. Within the broader taxonomy, a buck regulator belongs to switching regulators, which are a subset of DC-DC converters, which in turn are a type of voltage regulator under the power management IC umbrella. The LT3971 features Burst Mode operation that consumes only 2.8µA of quiescent current while regulating with no load, making it ideal for always-on applications and battery-powered systems where standby current is critical. The accurate 1V threshold enable pin allows the regulator to be shut down, reducing input supply current to 700nA, which preserves battery life during deep sleep states. A capacitor on the SS pin provides programmable soft-start, controlling inrush current at power-up. A power good flag signals when VOUT reaches 91% of the programmed output voltage, useful for multi-rail sequencing in complex systems. The internal architecture uses a 1.9A peak switch current limit, providing headroom beyond the 1.2A continuous rating for transient loads. The high switching frequency capability (2MHz) allows use of compact inductors and ceramic output capacitors, minimizing the overall solution footprint — particularly valuable in space-constrained portable designs. The MSOP-10 exposed pad package offers a thermal resistance suitable for moderate power dissipation. Typical applications include automotive battery regulation, portable industrial instruments, distributed supply regulation, battery-powered devices, and always-on systems requiring low standby current. The wide 38V input range tolerates load-dump transients and industrial 24V rails. When designing, pay close attention to the inductor selection: choosing a shielded inductor with appropriate saturation current and DC resistance optimizes efficiency. Place input/output ceramic capacitors close to the IC and route the exposed pad directly to a copper pour for thermal management. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
LT3971EMSE#PBF - 38V, 1.2A, 2MHz Buck Regulator | Analog Devices
The Analog Devices LT3971EMSE#PBF is an adjustable-frequency monolithic buck switching regulator that accepts a wide input voltage range up to 38V and delivers up to 1.2A of output current in a 10-pin MSOP with exposed pad (MSE) package. It operates with a low quiescent current of only 2.8uA at no load, supporting battery-powered and always-on applications. The switching frequency is user-programmable from 200kHz to 2MHz, allowing optimization between efficiency and external component size. A buck (step-down) switching regulator is a type of DC-DC converter that efficiently reduces a higher DC input voltage to a lower DC output voltage by rapidly switching a power transistor and storing energy in an inductor. Buck regulators occupy the middle tier of the power-management hierarchy: DC-DC converter -> switching regulator -> buck converter -> power management IC. They are preferred over linear regulators in high-ratio step-down applications because they avoid the large (VIN-VOUT) x IOUT power dissipation inherent to LDOs, achieving typical efficiencies of 85-95%. Key features of the LT3971EMSE#PBF include low ripple Burst Mode operation for high efficiency at light loads, an accurate 1V threshold enable pin (with 700nA shutdown current), a soft-start pin for controlled inrush current, and a power-good flag that signals when VOUT reaches 91% of the programmed value. The internal compensation and 1.2A switch current rating simplify design while reducing external BOM count. The 10-pin MSOP exposed pad package provides a low thermal-resistance path, supporting full 1.2A operation in industrial temperature grades (E: 0C to 125C junction, -40C to 125C by design). Typical applications include automotive battery regulation, industrial 24V bus point-of-load conversion, distributed power systems, portable battery-powered equipment, and always-on alarm/keep-alive supplies where the 2.8uA quiescent current is critical. When designing with the LT3971EMSE#PBF, choose the inductor and input/output capacitors based on the programmed switching frequency and load transients; higher switching frequencies permit smaller inductors but trade off switch losses.
LT3971EMSE-3.3 - 38V, 1.2A, 2MHz Buck Regulator | Analog Devices
The Analog Devices LT3971EMSE-3.3#PBF is a 38V, 1.2A, 2MHz monolithic step-down switching regulator with a fixed 3.3V output, packaged in a 10-lead MSOP with exposed thermal pad. It accepts a wide 4.3V to 38V input range, features only 2.8 µA quiescent current, and uses low-ripple Burst Mode operation to maximize efficiency at light loads. A buck (step-down) switching regulator is a DC-DC converter that produces a lower output voltage than its input by rapidly switching an inductor and storing energy in that inductor, then releasing it through a rectifier into an output capacitor. Buck regulators sit within the power management IC hierarchy (buck -> DC-DC converter -> voltage regulator -> power management IC) and are favored over linear regulators for their high efficiency, especially when VIN significantly exceeds VOUT. The LT3971 family is purpose-built for automotive and industrial applications where high input transients and very low standby drain matter. Key features include a programmable switching frequency from 200 kHz to 2 MHz, internal 1.2A switch, 2.8 µA Iq with output regulating at no load, fixed 3.3V or 5V and adjustable versions, internal compensation, and internal boost diode. The 10-lead MSOP-EP package offers a thermal resistance suitable for sustained 1.2A operation when properly footprinted, and the exposed pad must be soldered to a sufficiently large copper pour. Architecturally the LT3971 uses a current-mode control loop with a precision reference and an integrated power switch. The very low IQ allows it to maintain output regulation while drawing only micro-amps from the battery, and Burst Mode operation skips switching cycles at light load to keep efficiency high and output ripple low. Programmable frequency up to 2 MHz enables designers to choose frequencies above the AM band or outside sensitive IF bands, and to use small ceramic capacitors and inductors. Typical applications include automotive battery-powered systems, portable instruments, industrial control loops, and any 12V/24V supply rail that must deliver 3.3V with high efficiency. Its wide input range also makes it ideal for load-dump tolerant designs and battery-powered equipment that must operate down to deeply discharged battery voltages. When designing with this part, ensure the exposed pad is soldered over adequate copper (typically >=1 square inch) to keep junction temperature within ratings. Keep the input capacitor loop short to minimize ringing on the SW node, and choose an inductor with low DCR to preserve efficiency. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes that are not found in the manufacturer datasheet alone, accelerating component selection.
LT3971EMSE-3.3#PBF - 38V, 1.2A, 2MHz Buck Regulator | Analog Devices
The Analog Devices LT3971EMSE-3.3#PBF is an adjustable-frequency monolithic buck switching regulator that accepts a wide input voltage range up to 38V and delivers a fixed 3.3V output at up to 1.2A, housed in a 10-pin MSOP with exposed pad (MSE) package. The device features a 2.8 µA quiescent current, low-ripple Burst Mode operation, and a switching frequency up to 2 MHz, enabling compact designs with small inductors and ceramic capacitors. A buck (step-down) switching regulator is a DC-DC converter that efficiently reduces a higher DC input voltage to a lower DC output voltage by rapidly switching a power transistor and smoothing the resulting pulse train with an LC filter. The LT3971 family occupies the hierarchy: buck regulator → switching regulator → DC-DC converter → power management IC → semiconductor. Compared with linear regulators, buck regulators achieve much higher efficiency at large VIN/VOUT ratios, making them preferred for battery-powered and automotive systems where thermal dissipation is a concern. The LT3971's key features include a 4.3V to 38V input range, integrated power switch, 700 nA shutdown supply current (via an accurate 1V threshold enable pin), programmable soft-start with a capacitor on the SS pin, and a power-good flag that asserts at 91% of the programmed output voltage. The MSE package combines a small 10-pin MSOP outline with an exposed thermal pad for low thermal resistance. Internally, the LT3971 uses a current-mode control topology with Burst Mode operation that allows the regulator to maintain output voltage with only 2.8 µA quiescent current at no load - ideal for always-on battery systems. The high 2 MHz switching capability supports small inductor and capacitor selection, while the 38V absolute maximum input accommodates load-dump and cold-crank transients in 12V automotive rails. Typical applications include automotive battery-powered systems, industrial control supplies, portable instrumentation, distributed supply regulation in 24V industrial buses, and always-on housekeeping rails in IoT nodes. The wide VIN range also suits solar and telecom point-of-load regulation downstream of a higher-voltage bus. When designing, prioritize input bulk capacitance to handle inductor ripple, place the BST capacitor close to the SW and BST pins, and use a low-ESR ceramic output capacitor for ripple performance. The exposed pad must be soldered to a sufficiently large copper pour to keep junction temperature within the 125°C limit. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
LT4276AHUFD#PBF - LTPoE++ PoE PD Controller 90W | Analog Devices
The Analog Devices LT4276AHUFD#PBF is an LTPoE++/PoE+/PoE powered device (PD) forward/flyback controller with integrated switching regulator, housed in a 28-pin QFN (4x5) package. The LT4276A variant employs the LTPoE++ classification scheme and is capable of receiving 38.7W, 52.7W, 70W, or 90W of delivered power at the PD RJ45 connector, making it one of the highest-power PoE PD controllers available on the market for IEEE 802.3 and LTPoE++ systems. A Power over Ethernet (PoE) PD controller is a specialized interface IC that negotiates power classification with a Power Sourcing Equipment (PSE) over Ethernet cabling and then manages hot-swap, inrush, and DC-DC conversion downstream. Within the broader hierarchy, the LT4276AHUFD#PBF sits at the intersection of two domains: Power Management (DC-DC controller) and Interface ICs (Ethernet/PoE PHY interface). It supports both isolated forward and flyback topologies with synchronous rectification, enabling high-efficiency conversion from the 48V PoE rail to downstream logic voltages. Key features include a 60V absolute maximum VPORT rating with 2 mA typical operating current, an integrated 300 kHz switching oscillator, and pin-for-pin compatibility with the LT4276B and LT4276C family members that target standard PoE+ (25.5W) and PoE (13W) classifications. Auxiliary power support allows the PD to draw supplemental current from a local supply when PoE power is unavailable, while signature detection, classification, and disconnect functions are handled autonomously per IEEE 802.3at/af. Architecturally, the LT4276A combines an analog PD interface front-end with a current-mode PWM controller. The front-end performs detection (25k signature), classification (single or multi-event for LTPoE++), and disconnect monitoring using external pass-FETs. The integrated 300 kHz oscillator drives a synchronous gate driver pair that can be configured for forward or flyback topologies with an optocoupler-based feedback loop for isolated outputs, supporting high-efficiency designs above 90% at full load. Typical applications include 802.11ax/Wi-Fi 6 access points, high-power PTZ security cameras, PoE-powered LED lighting fixtures, industrial IoT gateways, digital signage displays, and any PD that requires 60W to 90W class power delivery over standard CAT5e/CAT6 cabling. The wide VPORT tolerance simplifies surge protection design using TVS diodes and PTC fuses per IEC 61000-4-5 requirements. When designing with this device, ensure the high-side pass-FET is rated for at least 100V VDS to survive line surge events and that the switching transformer primary inductance is sized for the chosen topology. Auxiliary supply detection via the AUX pin must be debounced to avoid hot-plug glitches during PoE-to-aux transitions. This page synthesizes distributor pricing, drop-in alternatives across the LT4276 family, and practical design notes that extend the manufacturer datasheet with sourcing and application-level guidance.
LT4276AHUFD#TRPBF - 90W LTPoE++ PD Controller, QFN-28 | ADI
The Analog Devices LT4276AHUFD#TRPBF is an LTPoE++/PoE+/PoE powered-device (PD) controller with an integrated isolated switching regulator controller, housed in a 28-pin QFN (4mm x 5mm) package. It supports the LTPoE++ classification scheme, enabling delivery of 38.7W, 52.7W, 70W or 90W at the PD RJ45 connector, and is backwards compatible with IEEE 802.3af (13W) and 802.3at (25.5W) PD signatures. Operating from a maximum input voltage of 60V over -40C to +125C, the LT4276A variant is the high-power member of the pin-compatible LT4276 family. A Power over Ethernet (PoE) PD controller is a device that negotiates power classification with a Power Sourcing Equipment (PSE) endpoint over an Ethernet cable, then enables a downstream DC-DC converter to deliver isolated, regulated power to the load. Within the system hierarchy, the LT4276 sits between the RJ45 magnetics and the isolated switching regulator - functionally a PoE interface IC plus SMPS controller in one. It belongs to the power-management IC category, and supports both forward and synchronous flyback topologies with auxiliary-power input for redundant supplies. Key features include on-chip signature resistor, programmable class timing for LTPoE++ detection, an integrated hot-swap FET driver, synchronous MOSFET gate drivers for both primary and secondary sides, an auxiliary power input for supply ORing, and an opto-coupler interface for primary-side regulation. The device is pin-compatible across the LT4276 family, allowing board reuse for 13W/25.5W/38.7W/52.7W/70W/90W PD designs with only the firmware classification resistor changed. Architecture-wise, the LT4276 combines a 100V-rated hot-swap control path, an 8-event classification engine, and a current-mode SMPS controller with programmable slope compensation. The synchronous-rectifier driver eliminates the secondary-side diode drop, lifting efficiency by 3-6% at 90W versus diode-rectified flyback designs. Auxiliary input support enables seamless failover between PoE and a local 24-48V supply. Typical applications include 802.11ax Wi-Fi 6/6E access points, 5G small-cell radio units, PTZ security cameras, industrial PoE lighting controllers, and IEEE 802.3bt-ready fanless embedded PCs. In all these use cases the LT4276A's 90W capability removes the need for local AC adapters. A key design consideration is thermal management of the QFN-28 package at sustained 90W: the exposed pad must be soldered to at least 1 sq-in of top-layer copper and four thermal vias to an inner plane to keep junction temperature below 125C. Designers should also honor the 100V absolute-maximum transient on the input during hot-plug events. This page synthesizes current distributor pricing, drop-in alternatives across the LT4276 family and competitors, and practical thermal/layout guidance that complements the manufacturer datasheet.
LT4276AIUFD - LTPoE++/PoE+/PoE PD Forward/Flyback Controller | Analog Devices
The Analog Devices LT4276AIUFD is an LTPoE++/PoE+/PoE Powered Device (PD) forward/flyback controller in a 28-pin QFN (4x5) package. The LT4276A variant supports LTPoE++ classification for receiving 38.7W, 52.7W, 70W, or 90W at the PD RJ45 connector, in addition to standard 802.3at (PoE+) and 802.3af (PoE) modes. The IC integrates an isolated switching regulator controller capable of synchronous operation in both forward and flyback topologies with auxiliary power support. A Power-over-Ethernet (PoE) Powered Device controller is a specialized power management IC that negotiates power delivery from an Ethernet switch or midspan injector and converts the 48V PoE rail into the regulated voltages required by the PD load. PoE controllers belong to the broader class of Power Management ICs (PMICs), specifically within the PMIC > Power Over Ethernet (PoE) Controllers family. They sit between the RJ45 magnetics and the downstream DC-DC converter, implementing detection, classification, inrush limiting, hot-swap FET control, and isolation handoff to a switching regulator. Key features of the LT4276A include: integrated 100V Hot Swap FET, support for legacy high-power Mode A and Mode B operation, programmable inrush current, soft-start, and an auxiliary supply input that allows automatic takeover from a local 24V/48V supply. The auxiliary input also enables operation without the PD interface (wall-adapter mode). The forward topology is preferred for higher output power (>40W) because it transfers energy efficiently through a single primary-side switch, while the flyback topology suits lower-power PDs requiring multiple output rails. Typical applications include high-power 802.3at/LTPoE++ powered devices such as 802.11ax Wi-Fi 6/7 access points, PTZ surveillance cameras, industrial PoE lighting, 5G small-cell radios, and digital signage. The auxiliary input makes it well suited to enterprise access points that must remain operational during PoE outages via a wall adapter. According to the manufacturer datasheet, the LT4276 family is pin-for-pin compatible, allowing designers to migrate between A/B/C variants and PoE+/LTPoE++ modes without PCB rework. A critical design consideration is thermal management at 90W LTPoE++ power levels: the 28-QFN (4x5) package requires adequate copper pours on the PCB to dissipate the Hot Swap FET losses. Designers should also size the TVS protection on the Ethernet lines per IEEE 802.3 to withstand 6 kV surge events. The auxiliary supply input must be back-biased with a Schottky diode to prevent reverse conduction into the wall adapter during PoE operation. This page synthesizes distributor pricing, pin-for-pin drop-in alternatives from the LT4276 family, and practical design notes not found in the manufacturer datasheet.
LT4295IUFD - IEEE 802.3bt PoE PD Controller | Analog Devices
The Analog Devices LT4295IUFD is an IEEE 802.3af/at/bt-compliant powered device (PD) interface controller with an integrated forward/flyback switching regulator controller, housed in a 28-pin QFN (4x5 mm) package, rated for 60V operation with a 214 kHz switch/clock. A powered device interface controller is the circuitry that a PoE-powered endpoint (such as an IP camera, wireless access point, or network switch port device) uses to safely receive power over Ethernet cabling. It performs detection, classification, and inrush current limiting per the IEEE 802.3 standard, then hands off to a DC-DC converter stage that converts the 37V to 57V PoE input down to usable system rails. Within the power-management hierarchy, the LT4295 belongs to the PD controller plus switching-regulator-controller class of power over Ethernet ICs. Key differentiating features include support for IEEE 802.3bt Type 3/Type 4 power levels via the T2P output, which indicates the number of classification events received during 802.3bt mutual identification and power negotiation. The LT4295 primarily targets single-signature PD topologies, eliminating the need for a second PD controller, and may also be deployed in dual-signature applications. The device supports both forward and flyback power supply topologies, and flyback operation supports No-Opto feedback, removing the optocoupler and its associated drift and aging concerns. Technically, the LT4295 drives an external low-RDS(on) N-channel hot swap MOSFET for controlled inrush and overcurrent protection, and supports LT4320/LT4321 ideal diode bridges to extend end-to-end power delivery efficiency. Auxiliary input voltages can be accurately sensed with just a resistor divider connected to the AUX pin, enabling seamless auxiliary-power-to-PoE switchover in hybrid powered designs. Typical applications include IEEE 802.3bt PoE+ powered IP surveillance cameras, 802.11ax wireless access points, PoE LED lighting drivers, and network intercom or building automation endpoints. The wide 60V rating provides margin over the 57V PoE bus. Design consideration: because the LT4295 controls an external hot swap MOSFET, ensure the MOSFET SOA covers the bulk-capacitor inrush transient, and place the VCC decoupling capacitor close to the VCC and GND pins as the datasheet layout guidance specifies. This page synthesizes distributor pricing, drop-in alternatives, design notes, and application guidance not found together in the manufacturer datasheet.
LT4295IUFD#PBF - IEEE 802.3bt PoE PD Controller | Analog Devices
The Analog Devices LT4295IUFD#PBF is an IEEE 802.3af/at/bt-compliant Power over Ethernet (PoE) powered device (PD) interface controller with an integrated forward/flyback switching regulator controller, delivered in a 28-pin QFN (4x5 mm, UFD) package with exposed pad. It supports PoE (802.3af), PoE+ (802.3at) and 802.3bt Type 3/4 power levels up to 71.3W, operating from a 60V-rated input rail. A PoE powered-device controller is the interface circuit that performs detection, classification, and inrush-current limiting on the power delivered over the Ethernet cable, then manages the downstream isolated (or non-isolated) DC-DC conversion. In the power-management hierarchy it sits between the Ethernet magnetics/diode bridge and the point-of-load converters, combining PD interface and PWM control in a single power management IC. Key features include IEEE 802.3bt mutual identification with a T2P output that indicates the number of classification events received, single-signature PD topology support that eliminates the need for a second PD controller, and an integrated switching regulator controller supporting both forward and flyback topologies for high efficiency power conversion. Technically, the LT4295 integrates a precision detection/classification engine with a current-mode PWM controller, allowing the entire powered-device front end and primary-side conversion control to be handled by one IC. The 60V rating and rugged hot-swap style inrush control protect the PD interface from cable surge events, while programmable oscillator frequency and soft-start allow optimization of transformer size and EMI signature. Typical applications include IEEE 802.3bt Type 3/4 powered devices such as security cameras, wireless access points, IP phones, LED luminaires, and industrial network nodes. Demonstration Circuit 2476A pairs the LT4295 with the LT4321 ideal diode bridge controller as a reference design. Design consideration: pair the LT4295 with the LT4321 PoE ideal diode bridge controller to minimize bridge diode losses and improve overall PD efficiency, especially at 802.3bt power levels. This page synthesizes distributor pricing, verified drop-in alternatives, practical design notes, and application guidance not found together in the manufacturer datasheet.
LT4295IUFD#TRPBF - 802.3bt PoE PD Interface Controller | Analog Devices
The Analog Devices LT4295IUFD#TRPBF is an IEEE 802.3af/at/bt Power over Ethernet (PoE) powered device (PD) interface controller with an integrated forward/flyback switching regulator controller, rated for 60V operation and up to 71.3W power delivery, housed in a 28-pin QFN (4x5 mm) package with exposed pad. A PoE PD interface controller is the power-management front end of a powered device such as a security camera, wireless access point, or IP phone. It sits at the top of the PoE power hierarchy: IEEE 802.3 standard -> Power Sourcing Equipment (PSE) -> Powered Device interface -> DC-DC converter. The PD interface performs detection, classification, inrush current limiting, and load disconnect per the IEEE 802.3af (PoE), 802.3at (PoE+), and 802.3bt (PoE++) specifications, then hands off regulated power to the switching regulator stage. Key features of the LT4295 include full IEEE 802.3bt (Type 3/Type 4, up to 71.3W single-signature) compliance, an integrated forward/flyback controller that eliminates a second controller IC, and support for external low-RDS(on) hot-swap N-channel MOSFETs to minimize power loss. Auxiliary input sensing via a simple resistor divider on the AUX pin allows seamless wall-adapter fallback, and compatibility with LT4320/LT4321 ideal diode bridge controllers extends end-to-end efficiency by eliminating diode bridge drops and costly heatsinks. Technically, the part integrates detection/classification state machines, a hot-swap FET gate driver, and a current-mode switching regulator controller with current-threshold control (ITHB) and feedback (FB31) pins for flyback transformer regulation. It primarily targets single-signature PD topologies but can be deployed in dual-signature designs in consultation with Analog Devices applications engineering. Typical applications include 802.3bt IP cameras, 60W/71W wireless access points, VoIP phones, PoE LED lighting, and industrial network nodes requiring wall-adapter auxiliary power. A key design consideration: the forward/flyback controller uses an external primary FET, so peak current set by ITHB and transformer design determine delivered power; follow the RFFSDLY (5.23k ohm typ.) fault-timing guidance in the datasheet. This page synthesizes distributor pricing, same-family drop-in alternatives, and practical design notes beyond what the manufacturer datasheet alone provides.
LT6657AHMS8-5#PBF - 5V 1.5ppm/°C Low Noise Series V-Ref | ADI
The Analog Devices LT6657AHMS8-5#PBF is a precision series voltage reference IC delivering a fixed 5 V output with ±0.1 % initial accuracy, 1.5 ppm/°C maximum temperature drift, and 0.5 ppm peak-to-peak noise in an 8-pin MSOP package with exposed pad. The device sources up to 10 mA and sinks up to 10 mA (per the LT6657 family datasheet), making it a versatile buffered reference for both ADC/DAC rails and instrumentation front ends. A series voltage reference is a type of precision shunt reference that internally regulates the output using an active buffer, providing a much lower dropout than classic Zener or two-terminal shunt topologies. Within the broader taxonomy, a series reference falls under voltage reference -> power management IC -> semiconductor. The buffered output allows direct connection to high-imprecision ADC reference pins, instrumentation amplifier reference nodes, and precision data-acquisition analog supplies, eliminating the need for an external op-amp buffer stage. Key features of the LT6657 family include advanced curvature compensation that gives predictable drift behavior across the full -40 °C to +125 °C operating range, very low temperature-cycling hysteresis (helping long-term system stability), and a wide operating supply range of up to 36 V (per the LT6657 datasheet). The combination of low noise, low drift, and high output current makes the LT6657AHMS8-5#PBF especially attractive for industrial instrumentation, weigh scales, precision medical monitors, and laboratory data loggers. The device is built on a BiCMOS process that integrates a precision bandgap cell with curvature-compensation circuitry and a low-noise output buffer. Compared to legacy buried-Zener references, the LT6657 family offers lower quiescent current draw, no heater-zener warm-up drift, and substantially better long-term stability, while still achieving comparable noise performance. Typical applications include precision 16-bit to 20-bit ADC reference supplies (e.g., driving SAR and sigma-delta converter REFIN pins), high-resolution DAC reference inputs, 4 mA to 20 mA loop transmitters, industrial pressure and temperature transmitters, bench-top multimeter reference rails, and medical instrumentation front ends where reference accuracy directly impacts clinical readings. When designing with the LT6657AHMS8-5#PBF, add 0.1 µF to 10 µF decoupling close to the supply pin and a 1 µF to 10 µF output capacitor for stable regulation. The exposed thermal pad must be soldered to the PCB ground plane to meet the datasheet's thermal specifications. This page synthesizes distributor pricing, same-family drop-in alternatives, and practical design notes not found in the manufacturer datasheet, helping engineers quickly select and source the LT6657AHMS8-5#PBF.
LT665BIS6-1.25#TRMPBF - 1.25V Voltage Reference | Analog Devices
The Analog Devices LT665BIS6-1.25#TRMPBF is a fixed 1.25 V precision voltage reference with ±0.1% initial accuracy, 20 ppm/°C temperature drift, and a TSOT-23-6 surface-mount package. It is designed for low-power analog and mixed-signal circuits requiring a stable reference rail with minimal supply current. The verified distributor data identifies the device as a 1.25 V series voltage-reference IC with a 5 mA load-current rating. A voltage reference is a specialized component that creates an accurate, stable voltage against which other circuit voltages can be measured or controlled. It belongs to the voltage-reference hierarchy within power-management and signal-conditioning semiconductors. The LT665BIS6-1.25#TRMPBF provides a compact reference source for ADCs, DACs, sensor interfaces, precision amplifiers, and low-power embedded systems. The key verified features are the fixed 1.25 V output, ±0.1% initial accuracy, and 20 ppm/°C temperature drift. The LT6656 family is also described by Analog Devices as drawing less than 1 μA of supply current and operating with a supply voltage within 10 mV of the output voltage. The 1.25 V version uses a 2.2 V test supply in the cited datasheet excerpt, while the family documentation states operation from 1.5 V to 18 V depending on output option, load current, and temperature. Because the reference is intended for precision analog systems, stable layout and decoupling are important. The manufacturer datasheet specifies a 0.1 μF input bypass capacitor within one inch of the input pin and recommends an additional 2.2 μF capacitor when source impedance is high or the reference drives heavy loads. These measures reduce supply noise and help preserve reference stability. Typical applications include sensor signal conditioning, precision data acquisition, low-power instrumentation, industrial control, and battery-powered measurement systems. The small TSOT-23-6 package supports compact PCB layouts, while the low supply-current characteristic is useful when energy efficiency matters. The fixed 1.25 V output can serve as a convenient midpoint reference for analog systems operating from a higher supply rail. When selecting a replacement, engineers should verify output voltage, accuracy grade, temperature coefficient, package, pinout, supply range, load capability, and capacitor requirements. LT6656AIS6-1.25#TRMPBF is a same-family part with tighter stated initial accuracy, but it should not be assumed to be a drop-in replacement without checking the relevant datasheet details. This page combines verified distributor information, manufacturer documentation, application guidance, and comparison notes for engineering review.
LT8210IUJ - 100V 4-Switch Sync Buck-Boost DC/DC Controller | ADI
The Analog Devices LT8210IUJ is a 100V synchronous 4-switch buck-boost DC/DC controller with PassThru, supplied in a 40-QFN (6x6 mm) plastic package. It delivers up to 2.5 A average output current with a wide 2.8V–100V input and 1V–100V output range, and supports four operating modes: PassThru, forced continuous, pulse-skipping, and Burst Mode. The 1ku list price starts at $8.87 per the manufacturer page. A buck-boost DC/DC controller is a switch-mode power supply IC that steps the input voltage up or down while maintaining regulation across the transition. It belongs to the hierarchy switching regulator → DC-DC converter → power management IC → semiconductor, and is used whenever VIN may sit above, below, or equal to VOUT (for example, 12V automotive cranking or 24V industrial buses powering 24V, 12V, or 5V loads). Compared with single-topology buck or boost controllers, a 4-switch buck-boost keeps the output in regulation through the entire VIN range with a single magnetic, simplifying EMI and reducing PCB area. Key features of the LT8210IUJ include: 2.8V to 100V input operating range, 1V to 100V adjustable output, 400 kHz default switching frequency, integrated 4-switch synchronous FET drivers, and selectable PassThru that bypasses switching when VIN is close to VOUT to maximize efficiency. The device also provides current-mode control, programmable soft-start, and fault outputs including PG (power good) and FAULT, alongside a robust set of protection features (OCP, OVP, thermal shutdown). Internally, the LT8210IUJ uses a peak current-mode control architecture with four N-channel gate drivers, allowing the part to connect the input, output, and inductor in different topologies depending on mode. In PassThru, both high-side switches are held on so VIN connects directly to VOUT, eliminating switching loss when VIN ≈ VOUT. In Burst Mode, quiescent current drops for sleep/standby, making the part attractive for always-on systems. Typical applications include 24V/48V industrial bus regulation, automotive 12V battery and start-stop rails, redundant telecom hold-up supplies, and wide-range battery-powered equipment. For high-current multiphase designs, the pin-compatible LT8210-1 adds ISHARE for masterless current sharing across paralleled phases. When designing with the LT8210IUJ, observe the 100V absolute-maximum rating and select external MOSFETs and inductors with adequate voltage and saturation margin. Keep the high-current loop tight and follow ADI's reference layout to manage EMI in high-frequency buck-boost operation. This page synthesizes distributor pricing, parametric drop-in alternatives, and practical design notes not found on a single datasheet page.
LT8301ES5#TRMPBF - 42V No-Opto Isolated Flyback | Analog Devices
The Analog Devices LT8301ES5#TRMPBF is a micropower isolated flyback converter housed in a 5-lead TSOT-23 (ThinSOT) package, integrating a 65V/1.2A DMOS power switch with all high-voltage control circuitry on-chip. The device operates over a 2.7V to 42V input range and delivers up to 6W of isolated output power without requiring an opto-isolator or third winding for regulation. What is a flyback converter? A flyback converter is a switched-mode power supply topology that uses a coupled transformer/inductor to transfer power across an isolation barrier, storing energy during the switch on-time and releasing it during the off-time. Isolated flyback converters are essential when the output must be galvanically isolated from the input for safety or noise reasons, such as in industrial bus-powered sensors, medical patient-isolated rails, or interfaces crossing mains-voltage boundaries. Within the broader power management hierarchy, the LT8301 belongs to DC-DC converters -> isolated switching regulators -> power management ICs. Key features include boundary-mode switching for low primary-side current, internal loop compensation, a single external resistor programming the output voltage, and a quiescent current optimized for always-on applications. The 65V internal DMOS switch supports flyback transformers with high turns ratios, enabling wide VIN-to-VOUT conversion steps from a single stage. The boundary-mode control scheme minimizes switching losses while keeping the transformer core flux balanced. The LT8301 samples the isolated output voltage directly from the primary-side flyback waveform, eliminating the opto-coupler and TL431 reference typically required. This architecture reduces BOM count by four to six components, simplifies PCB layout, and improves long-term reliability by removing the opto-coupler whose CTR (current transfer ratio) drifts with temperature and age. Typical applications include isolated industrial sensor supplies, isolated gate-drive bias for IGBT/MOSFET bridges, isolated RS-485/RS-232 transceiver power, medical patient-isolated rails, and 4-20 mA loop-powered instrumentation. Designers choose the LT8301 when they need a small-footprint isolated rail without the cost, complexity, and reliability concerns of an opto-coupler. Design consideration: select the flyback transformer turns ratio together with the feedback resistor to program the desired VOUT, then verify boundary-mode operation across the full load range. Below minimum load the part enters burst-mode operation, which introduces low-frequency ripple that some noise-sensitive loads may require additional filtering to suppress. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, helping engineers select and source the LT8301ES5#TRMPBF quickly.
LT8316EFE#TRPBF - 560V No-Opto Flyback Controller | Analog Devices
The Analog Devices LT8316EFE#TRPBF is a micropower, high-voltage isolated flyback controller that operates from a wide 18V to 560V input range and eliminates the need for an opto-isolator in the regulation loop. Housed in a thermally enhanced 20-pin TSSOP-EP package with four pins removed for high-voltage spacing, the device samples the output voltage from a third winding on the flyback transformer, simplifying isolated supply designs. Background Knowledge: A flyback controller is a type of switching DC-DC controller that uses a coupled-inductor (transformer) topology to transfer energy from input to output while providing galvanic isolation. The 'no-opto' variant eliminates the traditional optocoupler + TL431 feedback chain by sensing output voltage indirectly through an auxiliary winding, reducing BOM cost, improving reliability (no optocoupler CTR aging), and shrinking PCB area. Within the power management hierarchy, the LT8316 sits in the isolated switching regulator category, between isolated DC-DC converters and general-purpose switching controllers. Key features include 560V maximum input voltage, low 75uA quiescent current at no load, quasi-resonant boundary mode operation for improved load regulation and reduced transformer size, internal 1.6ms soft-start, and a programmable undervoltage lockout (UVLO). The boundary-mode control scheme turns on the external MOSFET when the transformer flux has fully reset, minimizing switching losses and EMI while maintaining high efficiency across load. The TSSOP-EP package provides an exposed thermal pad for improved heat dissipation in continuous high-power designs. The LT8316EFE is engineered using a high-voltage BiCMOS process that integrates a 560V-rated startup regulator on-chip, eliminating the external bias supply typically required by competing controllers. The device drives an external N-channel MOSFET through a totem-pole gate driver, allowing the user to size the MOSFET for their specific output power requirement rather than being constrained by an internal switch rating. Typical applications include isolated telecom secondary-side bias supplies, industrial 24V/48V bus isolated sensors, automotive EV battery management system (BMS) isolated rails, and household smart-meter isolated interfaces. The 560V input rating comfortably covers 380V rectified mains and 400V automotive bus voltages. When designing with the LT8316EFE, transformer design is the most critical step - the third-winding turns ratio and primary inductance must be carefully selected per the datasheet design procedure to maintain regulation. An RCD snubber across the primary winding is strongly recommended to clamp leakage-inductance spikes within the MOSFET Vds rating. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
LT8331IMSE#PBF - 140V 0.5A Boost/SEPIC/Flyback Conv | ADI
The Analog Devices LT8331IMSE#PBF is a current-mode DC/DC converter with an internal 140V, 0.5A power switch, operating from a 4.5V to 100V input rail. It is housed in a 16-lead (12-pin exposed pad) MSOP package with thermal pad for enhanced heat dissipation. The device supports boost, SEPIC, flyback, and inverting topologies from a single feedback pin architecture. A switching converter (also called a DC/DC switching regulator or SMPS - Switch-Mode Power Supply) uses energy storage elements (inductors and capacitors) and a power switch to convert one DC voltage to another DC voltage with much higher efficiency than linear regulators. The LT8331 belongs to the boost/SEPIC/flyback/inverting sub-family of non-isolated/isolated-capable switching regulators, which sits within the broader power management IC category. These topologies are preferred over linear regulators when high step-up ratios, high step-down ratios, or negative rails are required, especially at input voltages above 30V. Key specifications include a programmable switching frequency range of 100 kHz to 500 kHz, 6 uA quiescent current in Burst Mode operation, a SYNC/MODE pin for external clock synchronization or Burst/pulse-skipping selection, and a BIAS pin that allows the IC to be powered from its own output for increased efficiency. The internal current-mode architecture provides stable operation across a wide range of input and output voltages. The LT8331 employs a high-voltage DMOS power switch with current-mode control and internal compensation. The unique single FB pin allows the same IC to be reconfigured for boost, SEPIC, flyback, or inverting configurations simply by changing the external component connections - a significant engineering advantage for multi-rail designs. The 100V max Vin+ tolerance supports 4:1 input range industrial bus systems and automotive load-dump transients. Typical applications include industrial 24V/48V bus converters, automotive power conditioning, isolated flyback bias supplies, negative voltage generators for op-amp and ADC rails, battery-powered systems requiring high step-up ratios, and telecom infrastructure. The wide input range makes it especially attractive for systems that must survive wide input transients. When designing with the LT8331, carefully calculate maximum switch voltage stress in flyback/SEPIC topologies - the 140V internal switch rating provides generous headroom but requires proper snubber design for reliable operation. Use the SYNC pin to synchronize multiple converters in noise-sensitive systems. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.