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LM2596S-ADJ - 3A Adjustable Step-Down Switcher | Texas Instruments
The Texas Instruments LM2596S-ADJ is a 150 kHz, 3 A step-down (buck) switching regulator in a 5-lead TO-263 (D2PAK, TO-263BA) surface-mount package with an adjustable output voltage from 1.2 V to 37 V. It accepts a wide 4.5 V to 40 V input, integrates the power switch, oscillator, and thermal-shutdown block, and only requires four external components to build a complete buck converter. A buck (step-down) switching regulator is a type of DC-DC converter that uses a power switch, inductor, and rectifier to efficiently lower an input voltage to a lower regulated output. Compared with linear regulators, buck converters dissipate far less power because they switch the pass element fully on or fully off, reaching typical efficiencies of 73% to 88% at 3 A. The LM2596 sits in the classic SIMPLE SWITCHER family: non-isolated, asynchronous, and easy to design around with standard 33 µH inductors and 220 µF output capacitors. Key features include a fixed 150 kHz internal oscillator, 3 A continuous output current, 4.5 V to 40 V input range, adjustable output from 1.2 V to 37 V (set by external feedback resistors), TTL-shutdown input, internal current limiting, and thermal shutdown. The 5-lead TO-263 (D2PAK) tab provides a low thermal-resistance path that can dissipate the 7 W to 15 W typical full-load losses when soldered to sufficient copper area. Internally, the LM2596 uses a fixed-frequency, peak-current-controlled control architecture with an external compensation network chosen by the output capacitor type. The datasheet specifies standard and high-efficiency design tables that pair 33 µH inductors with 220 µF output capacitors (standard) or 330 µF with Schottky rectifiers (high-efficiency), giving the designer a proven starting BOM. Typical applications include 24 V-to-5 V/3.3 V industrial bus conversion, automotive accessory power, hobby robotics and drone LiPo battery regulation, distributed 12 V PoE auxiliary rails, and DIY buck modules. With thousands of third-party modules built around the part, it remains the canonical first buck regulator most engineers cut their teeth on. When designing, follow the datasheet catch-diode selection carefully: a 3 A Schottky such as the MBR360 keeps efficiency high, while a 1N5822 or similar is acceptable for lower-frequency, lower-cost designs. Keep the input capacitor loop tight and never operate above 40 V input; add a TVS such as P6KE39A for transients beyond 40 V. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, giving engineers a single decision-ready view of the LM2596S-ADJ.
LM2596S-ADJ/NOPB - 3A, 40V Adjustable Buck Regulator | TI
The Texas Instruments LM2596S-ADJ/NOPB is a monolithic 3 A step-down (buck) switching voltage regulator in a 5-pin TO-263 (D2PAK) surface-mount package. Operating from a 4.5 V to 40 V input and delivering an adjustable output from 1.2 V to 37 V at up to 3 A, it integrates a 150 kHz fixed-frequency oscillator, an internal switch rated to 45 V/3 A, current limiting, thermal shutdown, and an ON/OFF control input. A buck (step-down) switching regulator is a DC-DC converter that uses an inductor and a switch to lower a higher DC input to a lower regulated DC output with much higher efficiency than a linear regulator. The LM2596 belongs to the SIMPLE SWITCHER family of power management ICs, sitting in the broader hierarchy of voltage regulator → DC-DC converter → power management IC → semiconductor. Its 150 kHz switching frequency allows the use of small, low-cost inductors and aluminum electrolytic output capacitors, simplifying BOM. Key features include 3 A continuous output current, 4.5 V to 40 V input range, 1.2 V to 37 V adjustable output, 150 kHz fixed-frequency operation, internal high-current switch, thermal shutdown and current-limit protection, and an enable/ON-OFF pin for sequenced power-up. Typical standby current is 80 µA in shutdown. Architecturally, the LM2596 uses a fixed-frequency voltage-mode control loop with a 0.2 V internal reference. The high-side NPN Darlington switch drops about 1.5 V at full load, and the device requires a flyback Schottky diode, an inductor, and input/output capacitors to complete a converter. Efficiency typically reaches 73–80% at 5 V/3 A from 12 V input. Because it is non-synchronous, designers choose a Schottky such as the 3 A 40 V SS34. Typical applications include 24 V industrial bus to 5 V/3.3 V point-of-load conversion, battery chargers, automotive accessory supplies (with input transient protection), distributed power systems, LED drivers, hobby robotics, and any design that needs a simple, rugged, low-BOM-count buck regulator. When designing with the LM2596, ensure the input voltage never exceeds 40 V (45 V abs max), keep the catch diode loop area small, and provide a 1 oz copper pour under the tab for thermal dissipation at sustained 2–3 A loads.
LM2596SX-ADJ/NOPB - 3A 150kHz Buck Regulator | Texas Instruments
The Texas Instruments LM2596SX-ADJ/NOPB is a SIMPLE SWITCHER step-down (buck) switching regulator delivering up to 3A of continuous output current from a 4.5V to 40V input, with an adjustable output from 1.2V to 37V. It is housed in a 5-pin TO-263 (D2PAK, KTT) surface-mount package with an exposed tab for thermal dissipation, operating from -40C to +125C. A buck converter, or step-down regulator, is a type of DC-DC switching voltage regulator that efficiently reduces a higher input voltage to a lower output voltage. It belongs to the power management IC family and uses a switching element, an inductor, and a freewheeling diode to transfer energy in controlled pulses, achieving far higher efficiency than linear regulators. The LM2596 is a non-synchronous buck, using an external Schottky diode for the freewheeling path, which keeps the design simple and low cost. Key features include the wide 4.5V to 40V input range, adjustable output down to 1.2V via an external resistor divider, 3A output capability with excellent line and load regulation, and a fixed 150 kHz switching frequency that allows small inductors and low component count. Internal frequency compensation, thermal shutdown, and current limiting protect against fault conditions. Efficiency reaches up to roughly 90 percent depending on input-output differential and load. Technically, the LM2596 uses voltage-mode PWM control with a nominal 150 kHz oscillator (110 kHz to 173 kHz range per datasheet). Only a few external parts are needed: an inductor, catch diode, and input/output capacitors, and TI documents standard inductor series for quick designs. Typical applications include point-of-load supplies for microcontrollers, FPGAs, and DSPs, 12V and 24V industrial bus regulation, battery-powered equipment, automotive electronics, and popular adjustable DIY power modules. Design tip: size the inductor for continuous conduction mode at full load, use a Schottky diode rated for peak current, and solder the exposed tab to adequate copper area to keep junction temperature within limits. Pricing references are as of 2026-08-30.
LM2596SX-ADJ/NOPB-Q1 - 3A 150kHz Buck Regulator | TI
The Texas Instruments LM2596SX-ADJ/NOPB-Q1 is a SIMPLE SWITCHER step-down (buck) voltage regulator delivering up to 3A output current from a 4.5V to 40V input, with an adjustable output from 1.23V to 37V, in a TO-263 (KTT, DDPAK-5) surface-mount package. It operates at a fixed 150 kHz switching frequency and requires only four external components, minimizing BOM count and board area. A buck (step-down) switching regulator is a type of DC-DC converter that uses a switching element, inductor, and diode to efficiently reduce a higher input voltage to a lower output voltage. Unlike linear regulators, buck converters achieve high efficiency (up to 92% per TI datasheet) by minimizing power lost as heat, making them the workhorse of power management IC hierarchies for industrial, automotive, and consumer systems. Key features include 3A load capability with cycle-by-cycle current limiting, 150 kHz fixed-frequency operation that simplifies output filter design and keeps switching noise out of sensitive bands, a wide 4.5V to 40V input range tolerant of automotive load-dump transients, and a low 5 mA typical quiescent current. The adjustable version sets output via two external resistors (VOUT = 1.23V x (1 + R2/R1)). Internally, the LM2596 uses a voltage-mode PWM controller driving an NPN power switch, with internal thermal shutdown and current-limit protection. The TO-263 (D2PAK) package with exposed tab provides low thermal resistance to the PCB, supporting full 3A operation over -40C to +125C junction temperature. Typical applications include automotive auxiliary power rails, industrial 24V bus point-of-load conversion, and 5V/3.3V supplies for microcontrollers and logic. Note: verified distributor data confirms the standard LM2596SX-ADJ/NOPB; the -Q1 AEC-Q100 variant should be confirmed against TI ordering information for automotive builds. Design tip: keep the input capacitor, catch diode, and inductor loops short and place the feedback divider close to the ADJ pin; use a low-ESR output capacitor and Schottky diode rated for peak switch current.
LM2596T-12 - 3A 12V Buck Regulator 150kHz | Texas Instruments
The Texas Instruments LM2596T-12 is a SIMPLE SWITCHER 150 kHz 3 A step-down (buck) switching voltage regulator with a fixed 12 V output, housed in a 5-pin TO-220 (T) through-hole package with formed leads. It accepts an input voltage range of 4.5 V to 40 V and drives 3 A loads with excellent line and load regulation. A buck regulator is a type of switching DC-DC converter that steps a higher input voltage down to a lower output voltage using an internal power switch, an inductor, and a diode. Within the power management hierarchy, the LM2596T-12 belongs to the switching regulator family, sitting above linear regulators in efficiency and below power modules in integration. Switching regulators dissipate far less power than LDOs because the pass element switches rather than conducts continuously. Key features include a fixed 12 V output with plus/minus 4 percent maximum tolerance over line and load, a 3 A output load current capability, a low external component count requiring only a few passives, and a 150 kHz internal oscillator that permits smaller inductors than 52 kHz predecessors such as the LM2576. An ON/OFF pin enables low-current shutdown, and the family also offers 3.3 V, 5 V, and adjustable (1.2 V to 37 V) versions in the same footprint. Technically, the LM2596 is a monolithic bipolar IC integrating the reference, error amplifier, oscillator, and 3 A NPN switch. Its non-synchronous buck topology requires an external catch diode and inductor, achieving typical efficiencies of 80 to 92 percent depending on input and load conditions. Typical applications include industrial 24 V to 12 V rail conversion, automotive accessory power supplies, distributed 12 V logic and relay supplies, and bench or hobby power modules where a rugged through-hole part simplifies assembly. Design consideration: use the inductor values and diode recommendations from the manufacturer datasheet; the external Schottky diode must be rated for the peak switch current to prevent failure at full load. This page synthesizes distributor pricing, verified drop-in alternatives, pinout data, and practical design notes not consolidated in the manufacturer datasheet.
LM2596T-5.0/NOPB - 5V 3A Buck Regulator 150kHz | TI
The Texas Instruments LM2596T-5.0/NOPB is a SIMPLE SWITCHER 150 kHz step-down (buck) switching voltage regulator delivering a fixed 5 V output at up to 3 A from a 4.5 V to 40 V input, housed in a 5-pin TO-220 (NDH) through-hole package with formed leads. A buck (step-down) switching regulator is a DC-DC power converter that produces a lower output voltage from a higher input voltage by switching an internal power transistor at a fixed frequency and filtering the resulting waveform with an inductor and capacitor. Unlike linear regulators, switching regulators dissipate far less power as heat, making them the preferred choice whenever efficiency, thermal budget, or input-to-output voltage difference matters. The LM2596 sits within the broader hierarchy: switching regulator > DC-DC converter > voltage regulator > power management IC. Key features include the wide 4.5 V to 40 V input range that tolerates unregulated industrial supplies and 24 V buses, a fixed 5 V output with excellent line and load regulation, and 3 A output capability. The 150 kHz switching frequency allows the use of smaller inductors than older 50 kHz designs, while the external component count is deliberately low - a standard series of inductors from multiple manufacturers is pre-characterized for this part, greatly simplifying switch-mode power supply design. Internally the LM2596 is a monolithic IC integrating the power switch, oscillator, PWM control, and protection circuitry. The non-synchronous (external catch-diode) topology keeps the die simple and robust; efficiency at typical loads is high compared with equivalent linear solutions, significantly reducing heatsink requirements. The ON/OFF (enable) pin permits low standby-current shutdown. Typical applications include 5 V logic and microcontroller supplies from 12 V or 24 V rails, industrial automation power stages, battery chargers, and point-of-load conversion in instrumentation. The through-hole TO-220 package suits hand-soldered prototypes, repair, and high-vibration environments where solder joints benefit from larger mechanical land area. Design consideration: choose the catch diode (Schottky, rated above input voltage and 3 A), inductor, and output capacitors per the manufacturer datasheet tables; a poor inductor selection is the most common cause of instability or excessive ripple. This page synthesizes distributor pricing, drop-in alternatives, comparison tables, and practical design notes not found in the manufacturer datasheet, with data verified as of 2026-09-11.
LM26480QSQ-AA - Dual 1.5A Buck + Dual 300mA LDO PMIC | Texas Instruments
The Texas Instruments LM26480QSQ-AA is a multi-functional Power Management Unit (PMU) that integrates two 1.5A step-down DC/DC buck converters and two 300mA linear regulators (LDOs) in a 24-pin WQFN (RTW) 4x4mm package, qualified to the AEC-Q100 automotive standard. It operates from a 2.8V to 5.5V input rail and switches at a fixed 2 MHz (typical) frequency, enabling the use of small external inductors and ceramic output capacitors. Total deliverable current is approximately 2.4A across the four outputs. A Power Management IC (PMIC) is a single-package device that consolidates multiple DC/DC and LDO regulators so a multi-rail SoC, FPGA, or processor can be powered from one compact, factory-trimmed block. PMICs belong to the broader power-management category (DC/DC converters + LDOs + supervisors) and are widely used to reduce PCB area, simplify sequencing, and improve overall system efficiency versus a discrete regulator solution. The LM26480 sits in the mid-power PMIC segment, targeted at automotive infotainment, ADAS sensors, and industrial HMI boards. Key features include up to 96% typical buck efficiency, internal soft-start, undervoltage lockout (UVLO), current-limit protection, and thermal shutdown. Each output voltage is externally programmable through external resistor dividers (typical output range 0.8V to ~3.6V depending on rail), letting one PMIC serve processor core, I/O, memory, and auxiliary analog supplies. The high 2 MHz switching frequency pushes ripple noise above the AM-band, easing input filter design in automotive radio systems. Architecturally, the LM26480 uses two synchronous current-mode buck controllers with integrated high-side and low-side FETs, paired with two parallel-path linear regulators that can be derived from the bucks or directly from VIN. The device is rated for -40C to +125C junction operation, supports AEC-Q100 Grade 2 automotive reliability, and is offered in a thermally enhanced WQFN-24 (RTW) package with an exposed pad that ties to system ground for lowest thermal resistance. Typical applications include automotive infotainment head units, ADAS sensor modules, industrial HMI controllers, and portable/multi-rail SoC platforms where PCB real estate is at a premium. When designing with this part, ensure the exposed pad is soldered to a sufficiently large copper pour to keep junction temperature within the -40C to +125C window at full 1.5A per-buck load. The datasheet's recommended input capacitors (typically 10uF X5R ceramic) and output inductors (typically 1.0-2.2uH) should be selected with DC-bias derating in mind. This page synthesizes distributor pricing, AEC-Q100 cross-references, and practical layout notes not found in the manufacturer datasheet, helping engineers quickly decide if the LM26480QSQ-AA is the right PMIC for their next multi-rail design.
LM26480QSQ-AA/NOPB - Dual 1.5A Buck + Dual 300mA LDO PMU | TI
The Texas Instruments LM26480QSQ-AA/NOPB is a multi-functional Power Management Unit (PMU) that integrates two highly efficient 1.5A step-down DC/DC synchronous buck converters and two 300mA low-dropout (LDO) linear regulators in a 24-pin WQFN (RTW) package with 4x4 mm body size. The device operates over a 2.8V to 5.5V input range and supports switching frequencies up to 2 MHz, enabling compact designs with small external inductors and capacitors. A Power Management Unit (PMU) is an integrated circuit that consolidates multiple voltage rails - typically switching converters for high-current loads and LDOs for noise-sensitive analog supplies - into a single package. PMUs belong to the broader category of power management ICs (PMICs) and are commonly used in space-constrained, multi-rail systems such as automotive infotainment, industrial controllers, and portable embedded platforms where board area, BOM count, and reliability are critical design constraints. Key features of the LM26480 include external programmability for output voltages, soft-start, undervoltage lockout (UVLO), current limiting, and thermal shutdown protection. The two synchronous buck converters achieve typical efficiencies of 96%, while the two LDOs provide clean post-regulation rails for analog blocks. The QSQ-AA suffix denotes the automotive-qualified Q1 grade tape-and-reel packaging variant with 1.2mm maximum package height. The device architecture combines a fixed-frequency peak current-mode control loop for the buck converters with low-dropout pass-FET topology for the LDOs. The 2 MHz switching frequency allows the use of small 1uH inductors and 10uF ceramic output capacitors, minimizing total solution footprint. The LDO controllers accept input from either the buck outputs or the system rail and produce low-noise outputs suitable for RF, audio codec, or sensor analog supplies. Typical applications include automotive infotainment and instrument cluster power, FPGA and DSP core/IO rail generation, industrial HMI controllers, portable handheld devices, and SSD storage modules. The integration of four rails in a single 4x4 mm WQFN dramatically reduces PCB area versus discrete regulator implementations. Designers should observe thermal derating at full load across both buck outputs, ensure proper PCB layout to minimize switching noise coupling into the LDOs, and place input/output capacitors close to the IC. Refer to the TI LM26480 datasheet for the recommended inductor selection, feedback resistor tables, and PCB layout guidelines. This page synthesizes distributor pricing, AEC-Q100 cross-brand drop-in equivalents, and practical design notes not aggregated on individual manufacturer or distributor product pages.
LM26480SQ-AA/NOPB - Dual Buck + Dual LDO PMIC | Texas Instruments
The Texas Instruments LM26480SQ-AA/NOPB is a multi-functional Power Management Unit (PMIC) optimized for low-power digital applications, integrating two 1.5 A step-down DC/DC converters and two 300 mA LDO linear regulators in a single 24-pin WQFN (4x4 mm) package with exposed thermal pad. The device operates from a 2.8 V to 5.5 V input rail, switches at 2 MHz, and provides four independent outputs that can be sequenced via individual enable and power-good pins. This high level of integration eliminates the need for discrete point-of-load regulators in space-constrained designs. A Power Management IC (PMIC) is an integrated circuit that consolidates multiple voltage regulation functions into a single silicon die, replacing what would otherwise require several separate buck converters, LDOs, and sequencer ICs. PMICs sit at the top of the power tree hierarchy and serve as the central authority for rail generation, sequencing, and protection in a system. The LM26480 belongs to the multi-rail PMIC category, combining switching (high efficiency at large step-down ratios) with linear (low-noise post-regulation) topologies in one package. Key features include 2 MHz switching frequency (enabling small 1 µH inductors and minimal EMI footprint), individual enable inputs for each rail, dedicated power-good outputs for sequencing, automatic PWM/PFM light-load mode for high efficiency at low load currents, and integrated soft-start on every rail. The two synchronous buck converters deliver up to 1.5 A each with internal MOSFETs, while the two LDOs provide up to 300 mA of clean post-regulation for analog or RF rails. Thermal shutdown and current-limit protection are included on every output. The architecture pairs synchronous rectification buck stages with low-dropout linear post-regulators, allowing the system designer to combine high-efficiency conversion with low-noise analog supply generation. The 2 MHz switching frequency stays above the AM band, easing EMI filter design, while the exposed-pad package provides a low thermal resistance path to the PCB for dissipating combined regulator losses. According to the manufacturer datasheet, the part is qualified for -40 °C to +85 °C operation. Typical applications include portable media players, digital cameras, GPS/navigation handhelds, infotainment head units, and any battery-powered or USB-powered product that needs multiple regulated rails from a single Li-ion or 5 V source. The small 4x4 mm WQFN footprint suits smartphone-sized PCBs where area is at a premium. When designing with the LM26480SQ-AA/NOPB, ensure the input supply decoupling network (typically 1 µF + 10 µF ceramic) is close to the VIN pin, and route the AGND/DGND star-ground connection directly under the exposed pad. The PG/EN pins can be left floating if sequencing is not required. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found on the manufacturer datasheet alone.
LM2672M-5.0/NOPB - 1A, 40V Step-Down Switching Regulator | TI
The Texas Instruments LM2672M-5.0/NOPB is a fixed 5V output, 1A SIMPLE SWITCHER step-down (buck) switching regulator housed in an 8-pin SOIC package. It accepts a wide 8V to 40V input range, switches at 260 kHz, and uses TI's SIMPLE SWITCHER architecture to deliver high efficiency with a low external component count. The /NOPB suffix indicates a lead-free, RoHS-compliant matte-tin finish and TI's standard grade-1 qualification. A buck (step-down) switching regulator is a power management IC that converts a higher DC input voltage to a lower DC output voltage by rapidly switching an internal MOSFET and smoothing the resulting pulsed waveform through an LC low-pass filter. Compared with linear regulators, buck converters achieve far higher efficiency (typically 85-95% versus 30-60% for an LDO at large VIN-VOUT deltas) because they recycle energy through an inductor instead of burning it as heat. Within the broader taxonomy, buck regulators sit under DC-DC converters -> voltage regulators -> power management ICs -> semiconductors, and they remain the dominant topology whenever a regulated lower voltage must be derived from a battery, 12V/24V rail, or USB bus. The LM2672M-5.0/NOPB delivers a fixed 5V output at up to 1A, features internal frequency compensation, and includes cycle-by-cycle current limiting plus thermal shutdown. The 260 kHz fixed switching frequency permits the use of small surface-mount inductors and ceramic output capacitors, enabling compact PCB layouts. A wide 8V-40V input range makes the part tolerant of automotive load-dump transients and industrial 24V bus rails. The internal high-side DMOS switch is rated for the full 40V input without external protection, simplifying the BOM to typically just an inductor, two capacitors, a diode, and four feedback resistors are unnecessary because the 5V version is factory-trimmed. Typical applications include distributed 5V supply rails from a 12V or 24V system bus, point-of-load regulation after a front-end converter, automotive body electronics powered directly from the battery (with load-dump protection upstream), industrial sensor and actuator supplies, and battery-powered instruments requiring high step-down efficiency. Design considerations include choosing an inductor with adequate saturation current (typically >1.3A) and low DCR for best efficiency, and selecting a Schottky catch diode with reverse voltage greater than VIN(MAX). Output ripple depends on the LC filter; the manufacturer datasheet recommends a 100 uH to 470 uH inductor with low-ESR ceramic or low-ESR tantalum output capacitors. This page synthesizes distributor pricing, verified drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
LM2673S-ADJ/NOPB - 3A Adjustable Buck Regulator | Texas Instruments
The Texas Instruments LM2673S-ADJ/NOPB is a SIMPLE SWITCHER buck switching regulator with a 3 A output-current capability, an 8 V to 40 V input-voltage range, and an adjustable output from 1.2 V to 37 V. It is packaged in a 7-lead TO-263 D2PAK-style package with a tab for thermal conduction. A buck converter, also called a step-down switching regulator, reduces a higher DC input voltage to a lower regulated DC output. The LM2673 integrates the control functions, switching element, voltage reference, and adjustable-current-limit capability needed for a complete buck-converter power stage. It is intended for designers who need a straightforward 3 A regulator rather than a more complex configurable converter. The main features include one adjustable output, a 3 A load capability, an 8 V to 40 V operating input range, and adjustable output voltage. According to the Texas Instruments LM2673 product page, the device is the LM2673S-ADJ/NOPB adjustable-output version in the TO-263 (KTW) package with 7 pins. The NOPB suffix identifies the lead-free ordering option commonly used for industrial and commercial supply chains. This converter uses a step-down switching topology and requires external components including the inductor, input capacitor, output capacitor, and feedback resistors. The adjustable output is set by external resistor selection, while the current-limit function is also adjustable according to the device description. Designers should account for switching-node layout, ripple current ratings, thermal resistance, and the regulator’s maximum input and output limits. Typical applications include industrial control systems, telecom and networking equipment, automotive accessory power, instrumentation, and general 24 V input power conversion. Its 3 A rating makes it suitable for moderate-load rails rather than high-current server or processor supplies. The TO-263 tab assists heat transfer, but the thermal design still depends on PCB copper area, ambient temperature, switching frequency, and output voltage. For a drop-in replacement, compare the exact footprint, lead count, pin names, input range, output range, current rating, and adjustment method. LM2673 variants may share the family footprint, but not every related part has identical lead functionality. Verify the manufacturer datasheet and complete the thermal and compensation checks before substitution. This page combines verified distributor information, family-level technical context, practical design notes, and comparison guidance that is more useful for engineering evaluation than a basic distributor listing alone. Pricing and availability should be confirmed directly with an authorized distributor before procurement.
LM2675M-3.3/NOPB - 1A, 40V Buck Regulator, 3.3V Fixed | TI
The Texas Instruments LM2675M-3.3/NOPB is a SIMPLE SWITCHER® monolithic buck (step-down) switching regulator with a fixed 3.3V output, 1A load capability, and 6.5V to 40V input range, housed in an 8-pin SOIC (0.154" / 3.90mm width) package. It switches at 260 kHz, achieving greater than 90% efficiency while using only a handful of inexpensive external LC components. The device is part of TI's legacy LM267x family designed for low-component-count designs. 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 storing energy in an inductor. Buck regulators belong to the broader category of switch-mode power supplies (SMPS), which sit above linear regulators in the power management IC hierarchy. Compared to linear regulators that dissipate the VIN-VOUT differential as heat, switching bucks like the LM2675 deliver high efficiency across wide input ranges, making them ideal for 12V, 24V, and 36V industrial bus systems. Key features of the LM2675M-3.3/NOPB include 260 kHz fixed switching frequency that enables compact LC filter sizing, internal MOSFET switch, thermal shutdown, cycle-by-cycle current limiting, and a guaranteed ±1.5% output voltage tolerance (with the /NOPB grade). The SOIC-8 package provides adequate thermal performance when copper traces are used as a heatsink, owing to the high efficiency that minimizes internal dissipation. Architecturally, the LM2675 uses a voltage-mode PWM control loop with a precision bandgap reference and a high-side DMOS power switch monolithically integrated. The 260 kHz operation allows designers to use surface-mount inductors and small ceramic or low-ESR tantalum capacitors, dramatically shrinking the total solution footprint versus 150 kHz predecessors like the LM2596. Typical applications include 24V industrial sensor rails, distributed 12V-to-3.3V point-of-load (POL) conversion, automotive infotainment subsystems, and battery-powered systems with wide Vin swings. The wide 6.5V to 40V input range makes it well suited for 24V industrial buses and 12V automotive transients. A key design consideration is that the LM2675 is a hard-switching non-synchronous buck — efficiency is very high but ripple requires adequate output capacitance; choose low-ESR capacitors and follow the datasheet's recommended inductor and C_out values for stable operation.
LM2675M-5.0/NOPB - 1A, 5V Fixed SIMPLE SWITCHER Buck Regulator | Texas Instruments
The Texas Instruments LM2675M-5.0/NOPB is a SIMPLE SWITCHER high-efficiency 1A step-down (buck) voltage regulator with a fixed 5V output, accepting a 6.5V to 40V input range and housed in an 8-pin SOIC (D) package with 0.154 inch (3.90 mm) body width. Designed as a monolithic LMDMOS-based regulator, it requires a minimum number of external components to deliver a complete DC-DC conversion solution. Key specifications include a 1A continuous output current rating, a 260 kHz internal oscillator that enables small magnetics, and ±1.5% output voltage tolerance over the specified input and load range. The fixed 5V version is internally trimmed, while the ADJ variant sets output via an external resistor divider. The LM2675 family falls within the broader category of switching regulators (buck converter -> step-down regulator -> DC-DC converter -> power management IC), designed to replace older three-terminal linear regulators with significantly higher efficiency. The LM2675M-5.0/NOPB features built-in thermal shutdown, cycle-by-cycle current limiting, and an on/off enable input for power sequencing. The internal MOSFET switch and CMOS gate driver are integrated on the same die, eliminating the need for an external power switch. Its wide 6.5V to 40V input range supports 12V and 24V industrial bus rails directly, while the fixed 5V output is well-suited to powering logic, microcontrollers, and 5V subsystems. Typical applications include point-of-load regulation in industrial equipment, distributed 5V rails in automotive subsystems, distributed power architectures fed from 12V or 24V buses, and battery-powered systems where efficiency matters. The low external component count also simplifies manufacturing and reduces BOM cost. When designing with the LM2675, follow the datasheet inductor and capacitor selection guides closely - choosing a low-ESR input capacitor and a Schottky catch diode rated for the switching current is essential for stable operation. The PCB layout should keep the catch diode loop and the feedback trace short to avoid injecting switching noise into the output. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving engineers a single reference for sourcing, selection, and PCB-level integration of the LM2675M-5.0/NOPB.
LM2676S-ADJ/NOPB - 3A Step-Down Switching Regulator | Texas Instruments
The Texas Instruments LM2676S-ADJ/NOPB is a SIMPLE SWITCHER high-efficiency 3A step-down (buck) DC-DC regulator housed in a 7-pin TO-263 (D2PAK, KTW) surface-mount package with exposed thermal tab. It delivers an adjustable positive output from 1.2V to 37V from an 8V to 40V input rail, with up to 3A continuous load current and typical line/load regulation of better than 1%. A buck (step-down) switching regulator is a power-management IC that converts a higher DC input voltage to a lower DC output voltage by alternately storing energy in an inductor and releasing it to the load through a MOSFET switch. Within the system hierarchy, the LM2676 belongs to the SIMPLE SWITCHER family of non-isolated buck regulators, which sit within DC-DC switching regulators, which themselves are a sub-category of power-management ICs (PMICs). Compared with linear regulators (LDOs), buck converters like the LM2676 trade higher efficiency (typically 75-90%) for added complexity (inductor, catch diode, input/output capacitors) and produce switching ripple that must be filtered. Key features include a fixed 260 kHz switching frequency that allows use of small magnetic components, an internal DMOS power switch rated for 45V, a low quiescent current of 4.2 mA in standby, thermal shutdown, current limit, and an on/off enable control. The TO-263-7K-T package has a low thermal resistance (junction-to-case) of approximately 2 C/W, enabling full-power operation with a small copper heatsink area or none at all in low-duty applications. The device uses TI's classic buck control topology with voltage-mode control and internal compensation, simplifying external component selection. The feedback pin uses an external resistor network, while a soft-start capacitor controls soft-start discharge to limit inrush current during power-up. The high-side DMOS switch achieves low Rds(on) for high efficiency at 3A loads, making the LM2676S-ADJ/NOPB well-suited for medium-power point-of-load conversion. Typical applications include industrial 24V bus regulation, automotive accessory power (post-transient protection), battery-powered equipment, distributed 5V/12V/15V/24V rails in instrumentation, point-of-load regulation downstream of a rectifier, and high-current single-rail or front-end conversion. The wide input-to-output ratio and 3A capability cover most moderate-power distributed-power requirements. Design considerations: the catch diode with current limiting must be a Schottky type rated for the input voltage (e.g., 40V+ SS34), the inductor is typically 22-33 µH for most VIN/VOUT combinations, and the feedback divider must use 1% resistors. Because the LM2676 is not pin-compatible with newer TI WEBENCH-optimized regulators like the LMR33630, redesigns may be required for footprint migration, though the simple external BOM is widely documented and supported.
LM2755TMX - Charge Pump LED Driver, I2C, 3-LED, 18-DSBGA | TI
The Texas Instruments LM2755TMX is a charge-pump-based constant-current LED driver with I2C-compatible digital interface, capable of driving up to 3 LEDs with a total output current of 90 mA from a single-cell Li-ion source. Housed in a compact 18-ball DSBGA (Micro SMD) package, it integrates a fractional switched-capacitor (1x/2x) charge pump, three matched current sinks, and full I2C programming of brightness, ramp, and timing parameters. The device operates from a 2.7 V to 5.5 V input and supports diode waveforms with programmable rise time, fall time, high level, low level, delay, high time, and low time. A charge pump is a DC-DC switching converter that uses capacitors instead of inductors to step up or invert a voltage, multiplying the input by a fixed ratio (1x, 1.5x, or 2x). In a portable LED backlight system, the LED driver sits in the power management signal chain between the battery/power-management IC (PMIC) and the LED string. As a "linear regulator > voltage regulator > power management IC > semiconductor" hierarchy member, the LM2755 combines energy conversion with deterministic current regulation, making it ideal for thin display modules that cannot accommodate an inductor. Key features of the LM2755TMX include 90 mA total LED current across 3 outputs (30 mA per channel), 32-level I2C brightness control, programmable fade-in/fade-out ramps, and 1.2 MHz typical charge-pump switching frequency that allows the use of small 1 uF ceramic flying capacitors. An integrated soft-start limits inrush current, and over-temperature shutdown protects the device during fault conditions. The I2C interface supports 400 kHz Fast Mode and provides access to status registers for fault and identification. The LM2755 uses a dual-mode charge pump architecture that automatically switches between 1x pass-through and 2x boost to maximize efficiency across the Li-ion discharge curve, achieving roughly 93% peak efficiency at 3.7 V VIN driving white LEDs at 20 mA. Three independent current sinks with 1% current matching ensure uniform display brightness across RGB indicator or keypad applications. Typical applications include mobile-phone keypad backlighting, RGB status indicators, camera flash (low-current indicator LEDs), portable medical-device displays, and wearable activity-tracker indicator LEDs. The wide 2.7 V to 5.5 V input range also supports USB-powered and 1-cell Li-ion designs directly without a pre-regulator. When designing with this device, observe the 18-ball DSBGA layout guidelines strictly - the device requires a four-layer PCB with a continuous ground plane and vias under the thermal pad to dissipate up to 0.5 W. The I2C address is fixed (0xC8 7-bit), so multiple LM2755 instances on the same bus are not supported; for multi-channel designs, select the LM2756/LM2757 family instead. This page synthesizes distributor pricing, verified drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
LM2841XMK-ADJL/NOPB - 300mA 42V Step-Down DC/DC | Texas Instruments
The Texas Instruments LM2841XMK-ADJL/NOPB is a 300 mA, 42 V input-capable SIMPLE SWITCHER® step-down (buck) DC-DC regulator housed in a 6-pin Thin SOT-23 (TSOT-23-6, TI DDC package). It accepts 4.5 V to 42 V inputs and produces an adjustable output from 0.765 V up to 39.48 V, making it well suited to industrial and automotive load-dump-tolerant point-of-load regulation. According to the TI LM2841 product page, the family comprises the LM2840 (100 mA), LM2841 (300 mA), and LM2842 (600 mA), all built around a 0.765 V nominal feedback reference. A buck (step-down) DC-DC converter is a switch-mode power supply topology that efficiently converts a higher DC input voltage into a lower DC output voltage by rapidly chopping the input with an inductor-capacitor filter network, achieving efficiencies that linear regulators cannot match at large input-to-output differentials. Within the broader power management IC hierarchy, the LM2841XMK sits under DC-DC converters -> voltage regulators -> power management ICs -> semiconductors. The TSOT-23-6 (DDC) footprint places it firmly in the surface-mount QFN/SOT family, and its wide VIN range makes it a common choice for 12 V/24 V industrial bus and battery-powered applications. Key features of the LM2841XMK include a wide 4.5 V to 42 V continuous input range, an integrated MOSFET switch that keeps the BOM small, 300 mA continuous output current, a low 0.765 V feedback reference, internal compensation that removes the need for an external compensation network, and a shutdown (SHDN) pin that can implement soft-start with an external RC. Its 1.25 MHz nominal switching frequency allows small ceramic input/output capacitors and a tiny inductor, shrinking the total solution footprint to a few square millimeters on the PCB. Typical applications for the LM2841XMK include 12 V/24 V industrial sensor rails, battery chargers, LED drivers, distributed supply rails in point-of-load systems, and any application that needs to step a wide-range bus down to a logic-level rail. It is frequently selected over linear regulators when the input-to-output differential exceeds ~2 V because of its high efficiency. The thin SOT-23 package has a theta-2-JA around 90 C/W on a standard JEDEC test board, so careful copper-pour thermal management is required when dissipating more than ~0.5 W. When designing with the LM2841XMK, follow the manufacturer datasheet recommended inductor and capacitor values for your specific VOUT, and ensure the input capacitor handles the RMS ripple current at the 1.25 MHz switching frequency. Always check that the peak inductor current stays below the 0.5 A peak switch-current limit when the load transient peaks coincide with minimum VIN. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the TI datasheet alone.
LM2841YMK-ADJL - 300mA 42V Buck Converter | Texas Instruments
The Texas Instruments LM2841YMK-ADJL is a 300 mA, 42 V input-capable PWM DC/DC buck (step-down) switching regulator with adjustable output voltage (0.765 V minimum reference), housed in a 6-pin thin SOT-23 (TSOT-23-6 / DDC) package. It integrates a 0.9 ohm typical low-RDS(ON) internal power switch, enabling typical efficiency of 85 percent from wide-input industrial and consumer rails. The switching frequency is 1500 kHz nominal, allowing the use of small external inductors and ceramic output capacitors. What is a buck converter? A buck converter (step-down DC/DC switching regulator) is a power management device that uses an internal MOSFET switch, an inductor, and a capacitor network to convert a higher DC input voltage to a lower regulated DC output voltage with high efficiency. Buck converters sit in the power management taxonomy as: buck converter -> DC/DC switching regulator -> voltage regulator -> power management IC. They are preferred for higher step-down ratios where linear regulators (LDOs) waste excessive power as heat. Key features include a 4.5 V to 42 V wide input range that tolerates automotive load-dump conditions and 24 V industrial buses, internal compensation that eliminates most external compensation components, and built-in cycle-by-cycle current limit, thermal shutdown, and soft-start on the same enabling reference family. The thin SOT-23-6 footprint occupies approximately 9 mm² of board space, suiting space-constrained point-of-load applications. Architecturally, the device uses a fixed-frequency peak-current-mode control topology. The internal high-side switch commutates the inductor at 1.5 MHz, and the feedback loop regulates the output against the 0.765 V internal reference using an external resistor divider. The peak-current-mode control provides inherent cycle-by-cycle current limiting and simplifies loop compensation. Operating junction temperature spans -40 C to +125 C, supporting automotive and industrial environments. Typical applications include point-of-load regulation for 24 V industrial buses, powering microcontrollers and sensors from unregulated 12 V or 18 V sources, portable and battery-powered systems, LED constant-current drivers, and automotive infotainment and body electronics. The wide input range also supports wall-transformer-fed consumer electronics, telecom point-of-load rails, and distributed supply architectures. When designing with this regulator, ensure the input capacitor and bootstrap capacitor are placed close to the IC pins and that the inductor is sized for 1500 kHz operation (typically 4.7 uH to 22 uH). Calculate power dissipation by (I_OUT × V_DIODE) for the rectifying path and (I_OUT × VIN × (1 - VOUT/VIN)) for the high-side switch, then verify thermal margin against the 31.6 C/W theta_JA in TSOT-23. This page synthesizes distributor stock and pricing, drop-in alternatives across TI and competing brands, and practical PCB/thermal design notes not found in the bare datasheet.
LM2936BMX-3.3/NOPB - 50mA, 40V Ultra-Low IQ LDO | Texas Instruments
The Texas Instruments LM2936BMX-3.3/NOPB is a 50 mA, fixed 3.3 V output, ultra-low quiescent current low-dropout (LDO) linear regulator with reverse-voltage protection, packaged in an 8-pin SOIC (D). It is the tape-and-reel, Pb-free, RoHS-compliant variant of the LM2936-3.3 family and is qualified for automotive and battery-operated applications where standby current is critical. An LDO (Low-Dropout) linear regulator is a type of voltage regulator that maintains a stable output voltage even when the input voltage is only slightly above the output voltage. LDOs sit within the broader power management IC hierarchy as linear regulators (versus switching regulators), trading efficiency for simplicity, low noise, and very small quiescent current. The LM2936 family specifically targets always-on battery and automotive subsystems. Key features include a 5.5 V to 40 V (60 V transient-tolerant) input operating range, 3.3 V fixed output with ±3% accuracy over line, load, and temperature, 200 mV typical dropout at 50 mA, and ultra-low quiescent current of approximately 20 uA (typ) at light loads. The reverse-voltage protection block prevents damage from reversed battery or load-dump transients common in 12 V automotive rails, and internal current limit plus thermal shutdown provide additional robustness. The architecture uses a PNP pass element followed by a precision bandgap reference, allowing the regulator to operate with very low quiescent current while maintaining regulation down to small VIN-VOUT differentials. The -40C to +125C junction temperature range and automotive-grade qualification make it suitable for under-hood and body-control modules. Typical applications include automotive body electronics and ECU standby rails, battery-powered microcontroller sleep-mode supplies, keep-alive RAM retention in parking/telematics modules, HVAC sensor bias, and remote/keyless-entry receiver power. The 40 V rating also makes it well-suited to industrial 24 V bus systems. When designing with this device, keep input and output capacitors close to the pins and verify the dropout margin at minimum VIN. Reverse-polarity and load-dump events must still be mitigated externally for full automotive transient compliance. This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not consolidated on the manufacturer datasheet, enabling faster BOM decisions for 3.3 V always-on rails.
LM317AMDTX/NOPB - 1.5A Adjustable Linear Regulator, TO-252 | Texas Instruments
The Texas Instruments LM317AMDTX/NOPB is a 1.5-A, 40-V, high-accuracy adjustable three-terminal positive linear voltage regulator in a 3-pin TO-252 (DPAK) surface-mount package. It delivers adjustable output from 1.25 V to 37 V at up to 1.5 A with 1% output voltage accuracy and full overload protection including current limit, thermal shutdown, and safe-area compensation. The device is supplied on tape-and-reel (suffix TX) with the lead-free / no-PB (NOPB) finish. An adjustable linear regulator (often called a three-terminal regulator) maintains a stable output voltage set by an external resistor divider, while dissipating the difference between input and output voltage as heat. These regulators form the simplest building block in the power-management hierarchy: linear regulator -> voltage regulator -> power management IC -> semiconductor. They trade efficiency for low noise, simplicity, and low cost versus switching converters, and are ideal when a few watts of dissipation are acceptable and noise-sensitive analog or digital loads must share a clean rail. Key electrical characteristics include a 4.2 V to 40 V input range, 1.25 V to 37 V adjustable output, typical 1.5 A load current with peak capability exceeding 1.5 A, line regulation of 0.01%/V (typical), and load regulation of 0.1% (typical). Internal protection covers thermal-overload, short-circuit current foldback, and safe-operating-area compensation. The DPAK (TO-252) tab serves as the heatsink, allowing moderate dissipation directly into PCB copper without a discrete heatsink. Typical applications include local post-regulation after a switching converter, bench power supplies, battery chargers, LED current regulators, and industrial 24 V bus regulation. It is commonly used as a precision current source by setting R1 between VOUT and ADJ to program a constant 1.25 V across the sense resistor. When designing with the LM317AMDTX/NOPB, an input bypass capacitor is recommended if the regulator is more than 6 inches from the filter capacitor of the supply, and an output capacitor (tantalum or low-ESR aluminum) improves transient response. Calculate worst-case power dissipation as (VIN(max) - VOUT(min)) x IOUT(max) and ensure the copper area on the tab keeps junction temperature below 125 C. This page synthesizes distributor pricing, same-brand drop-in alternatives, cross-brand equivalents, and practical design notes not found in the manufacturer datasheet.
LM317DCYR - 1.5A Adjustable Positive Regulator | Texas Instruments
The Texas Instruments LM317DCYR is a three-terminal adjustable positive voltage regulator capable of supplying more than 1.5A over an output voltage range of 1.25V to 37V, housed in a compact SOT-223-4 surface-mount package. Only two external resistors set the output voltage, making it one of the most widely used linear regulators in electronics history. A linear regulator maintains a constant output voltage by dissipating excess power as heat. The LM317 is an adjustable linear regulator whose output is programmed by a resistor divider, with a fixed 1.25V reference between the output and adjustment pins. Linear regulators belong to the broader power management IC family, alongside switching regulators and LDOs, and are preferred in noise-sensitive circuits for their low output noise and fast transient response. Key features include typical line regulation of 0.01% and load regulation of 0.1%, plus internal short-circuit current limiting, thermal overload protection, and safe-area compensation. The device supports input voltages up to 40V, with a typical dropout voltage of about 2.5V at 1.5A load. The junction temperature range of 0C to 125C covers commercial and industrial requirements. Architecturally, the LM317 uses a bandgap reference and error amplifier. The 1.25V reference across the programming resistor makes the device double as a precise constant-current source, useful for LED driving and battery charging. The SOT-223-4 package offers good thermal performance with a reasonable PCB copper area, and the tab is connected to the output pin for direct heatsinking to a copper pour. Typical applications include adjustable bench power supplies, battery chargers, LED constant-current drivers, audio equipment, instrumentation, and industrial control systems where a stable adjustable rail is required. Design tip: maintain at least a 3V input-output differential for regulation, size copper pour for thermal dissipation, and bypass the adjustment pin with a capacitor to improve ripple rejection.
LM317LCPK - 100mA Adjustable Positive Regulator | Texas Instruments
The Texas Instruments LM317LCPK is a 3-terminal adjustable positive voltage regulator capable of supplying up to 100 mA over an output voltage range of 1.25V to 37V, housed in the compact SOT-89-3 (PK) package. It requires only two external resistors to set the output voltage, making it exceptionally easy to use in space-constrained designs. A linear voltage regulator is a type of voltage regulator that maintains a constant output voltage by dissipating excess power as heat. The LM317L belongs to the broader family of positive adjustable linear regulators, alongside fixed-output regulators like the LM78xx series and modern low-dropout (LDO) regulators. As a linear regulator, it offers low output noise and fast transient response, but is less efficient than a switching regulator when the input-to-output differential is large. Key features include the 100 mA output current, the wide 1.25V to 37V adjustable output, typical line regulation of 0.01%/V, and 30 uVrms output noise. Internal current limiting, safe-area compensation, and thermal overload protection are built in. The LM317LC series is characterized for a junction temperature range of 0C to +125C. Technically, the LM317L uses a bandgap reference and an error amplifier. The output voltage follows the classic formula VOUT = 1.25V * (1 + R2/R1) + IADJ * R2, with a 1.25V reference and 50 uA adjustment pin current. Typical quiescent (adjustment pin) current is low, and the SOT-89-3 tab provides improved thermal dissipation versus SOT-23 packages. Typical applications include on-board regulation for microcontrollers, analog sensor interfaces, low-power audio circuits, and battery-powered devices where a stable adjustable rail is required. Design tip: maintain at least 3V input-to-output headroom, keep input and output capacitors close to the device, and solder the tab to a copper pour for heat dissipation at higher VIN-VOUT deltas.
LM317LD13TR - 1.2-37V Adjustable LDO | STMicroelectronics
The STMicroelectronics LM317LD13TR is an adjustable positive linear voltage regulator with a 1.2 V to 37 V output range, low-current operation, and an SO-8 package. It is designed to regulate higher-voltage supplies down to a user-selected output using external resistors. The verified distributor listing identifies a 100 mA output-current configuration, while the datasheet result describes the device as a low-current adjustable regulator with a 1.2 V to 37 V range. Its positive output polarity, adjustable architecture, and internal thermal and short-circuit protection make it useful for low-power analog, instrumentation, control, and laboratory supply rails. The LM317LD13TR belongs to the LM317 family, whose defining feature is a simple three-terminal implementation: input, output, and adjustment. Unlike a switching regulator, the LM317 family provides low switching-related noise, but power dissipation depends on the difference between input and output voltage and load current. Applications include sensor excitation, reference rails, analog signal conditioning, small embedded supplies, and educational power-supply platforms. Because the SO-8 package is compact, PCB layout should provide adequate copper area and short, low-resistance paths for input and output connections. The adjustment pin requires a suitable compensation network to maintain loop stability, and the regulator should be checked for thermal rise at the maximum expected VIN, VOUT, and load. The LM317 family is also widely used where a simple, serviceable, and widely understood regulator topology is preferred over a more complex digital power solution.
LM317QDCYRQ1 - 500mA 40V Adjustable LDO | TI | Automotive
The Texas Instruments LM317QDCYRQ1 is an automotive-grade, positive adjustable linear voltage regulator delivering up to 500 mA of output current from a 40 V maximum input, packaged in a 4-pin SOT-223 (DCY) surface-mount package. As part of the LM317MQ family qualified for automotive applications, it provides a classic three-terminal adjustable regulator architecture with a 1.25 V reference voltage set by two external resistors. An adjustable linear regulator (LDO-style series pass regulator) is a type of voltage regulator that maintains a stable output voltage by controlling the voltage drop across an internal series pass transistor. Within the power management IC hierarchy, the LM317 family sits in the classic NPN-darlington floating regulator category, renowned for decades of use across industrial and automotive power rails. The 'Q1' suffix indicates AEC-Q100 qualification and automotive temperature support. Key features include a wide input voltage tolerance up to 40 V, 500 mA output current capability, internal thermal overload protection (thermal shutdown), and safe-operating-area current limiting. The floating architecture allows operation at high voltages, and the adjustable output enables a single design to cover multiple rail voltages simply by changing two resistors. Technically, the device regulates the 1.25 V bandgap reference between the output and adjustment (ADJ) pin. The load and line regulation benefit from the low reference current, and the ADJ pin current of approximately 50 uA must be accounted for in the output divider calculation for best accuracy. Standard 1% resistors typically achieve output accuracy within a few percent. Typical applications include automotive body electronics and infotainment auxiliary rails, industrial 12 V and 24 V bus post-regulation, and general-purpose adjustable bench or bias supplies where simplicity and robustness outweigh efficiency. Design consideration: the device is a linear regulator, so power dissipation equals (VIN - VOUT) x ILOAD. The SOT-223 tab should be soldered to a generous copper pour; verify junction temperature stays below the datasheet maximum at worst-case load and input voltage.
LM317T - 1.5A Adjustable 1.2-37V Regulator | STMicroelectronics
The STMicroelectronics LM317T is a three-terminal adjustable positive linear voltage regulator rated for 1.5A output current and an adjustable output range of 1.2V to 37V, supplied in a TO-220 package. It requires only two external resistors to establish the output voltage and provides internal current limiting, thermal overload protection, and safe-area compensation. An adjustable linear voltage regulator maintains a nearly constant output by operating a pass transistor in its linear region and correcting the output through feedback. The LM317T belongs to the linear regulator and voltage regulator branches of power-management ICs. Compared with switching regulators, it introduces little switching ripple and needs few external components, but its efficiency falls as input-to-output voltage difference and load current increase. Key electrical features include typical line regulation of 0.01% per volt and typical load regulation of 0.1%. The internal architecture regulates a nominal 1.25V reference between the output and adjustment pins. Internal current limiting limits fault current, thermal overload protection shuts down excessive temperature conditions, and safe-area compensation improves robustness when input and output conditions approach the pass transistor limits. The regulator uses a bandgap reference, error amplifier, and power pass transistor. Its output follows VOUT = 1.25V × (1 + R1/R2) plus the adjustment-pin current contribution, making resistor tolerance relevant to overall accuracy. The verified source data states an input-to-output differential range of 3V to 40V and a typical dropout voltage of 2V at a 1.5A load. Typical applications include adjustable laboratory supplies, battery chargers, constant-current sources, local regulation for audio and instrumentation, and general-purpose power rails. The TO-220 body is readily heatsinked, making the device practical when several watts must be removed, although allowable dissipation depends on junction temperature and thermal resistance. Designers should preserve at least the required input-to-output headroom, use a suitable heatsink, place input and output capacitors close to the device, and consider adjustment-pin bypassing for ripple rejection. Protection diodes may be needed when output capacitance creates discharge current through the regulator. This page also synthesizes verified source data, drop-in candidates, and practical engineering guidance beyond the basic datasheet description.