LT8609SIV#PBF - 42V 2A/3A Peak Sync Buck Regulator | Analog Devices
MPN: LT8609SIV#PBF ✓ AktifLT8609SIV#PBF Ringkasan
A buck switching regulator (step-down converter) is a type of DC-DC switching regulator that efficiently converts a higher DC input voltage to a lower DC output voltage using an internal switch, an external inductor, and control loop. Synchronous buck regulators use a MOSFET in place of the traditional freewheeling diode to reduce conduction loss and improve efficiency, especially at high load currents. The LT8609S sits within the power management hierarchy of: switching regulator -> DC-DC converter -> voltage regulator -> power management IC -> semiconductor.
Key features include a 1.7 µA quiescent current that makes the part ideal for always-on applications, a wide 3.0 V to 42 V input range that survives automotive load-dump transients, and a programmable output down to 0.782 V for powering modern low-voltage MCUs and SoCs. The part uses a constant-frequency peak current-mode architecture up to 2 MHz, and the SYNC/MODE pin allows synchronization to an external clock. Internal MOSFETs (top + bottom) eliminate the need for an external Schottky diode.
The LT8609S uses a peak current-mode control architecture with a precision reference and internal loop compensation, which simplifies schematic design by reducing the external component count to just an inductor, input/output capacitors, and feedback resistors. The 42 V absolute maximum input makes the part attractive for 12 V and 24 V industrial or automotive buses. The exposed pad on the TFQFN-16 package provides a low theta_JA thermal path for sustained 2 A operation.
Typical applications include automotive always-on systems, industrial 24 V sensor and actuator rails, battery-powered portable instruments, and general-purpose 5 V/3.3 V/1.8 V point-of-load conversion in telecom and factory automation. The low IQ also makes the part attractive for solar- or battery-energy-harvested systems.
When designing with the LT8609S, place the input capacitor as close as possible to the IN and GND pins to minimize switching loop area and EMI. Choose the inductor based on the 1.5 A to 3 A saturation current rating to handle the peak current-mode ripple. Use a feedforward capacitor (CFF) in parallel with the top feedback resistor to improve transient response when VOUT is well above the 0.782 V reference.
Alternatif penggantian untuk LT8609SIV#PBF — paket yang sama, pin-pada-pin kompatibel. Bagian paket yang berbeda memerlukan kerja ulang PCB diabaikan.
LT8609SEV#PBF
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
LT8609SIV#WPBF
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
LT8609SIV#TRPBF
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
LT8609SIV#PBF Rating Maksimal & Karakteristik Listrik
| Topologi | Synchronous Buck (Step-Down) |
| Rentang Tegangan Masukan | 3.0 V to 42 V |
| Rentang Tegangan Output | 0.782 V to V_IN (adjustable) |
| Continuous Output Current | 2 A |
| Peak Output Current | 3 A (less than 1 second) |
| Non-Switching Quiescent Current | 1.7 µA |
| Frekuensi Pengganti | Up to 2 MHz (programmable, synchronizable) |
| Tegangan Referensi | 0.782 V |
| Internal MOSFETs | Yes (synchronous top + bottom) |
| Paket | 16-TFQFN Exposed Pad |
| Tipe Mounting | Surface Mount |
| Suhu Hubung Kerja | -40 °C to +125 °C (LT8609SIV grade) |
| Status RoHS | Compliant (PBF suffix) |
Konfigurasi Pin LT8609SIV#PBF
| Pin produk 1 | AGND — Analog ground reference for the internal control circuitry |
| Pin produk 2 | FB — Feedback input to the internal error amplifier (0.782 V reference) |
| Pin produk 3 | RT — Timing resistor pin to program switching frequency |
| Pin produk 4 | SYNC/MODE — Synchronization input / Burst Mode or pulse-skipping mode selection |
| Pin produk 5 | EN/UVLO — Enable and undervoltage lockout threshold programming |
| Pin produk 6 | BST — Bootstrap pin for the internal high-side MOSFET gate drive |
| Pin produk 7 | SW — Switch node connection to the external inductor |
| Pin produk 8 | SW — Switch node (continued for higher current handling) |
| Pin produk 9 | PGND — Power ground return for the internal low-side MOSFET |
| Pin produk 10 | PGND — Power ground (continued) |
| Pin produk 11 | IN — Main input voltage supply (3.0 V to 42 V) |
| Pin produk 12 | IN — Input voltage (continued for higher current handling) |
| Pin produk 13 | PGND — Power ground (continued) |
| Pin produk 14 | PGND — Power ground (continued) |
| Pin produk 15 | PGND — Power ground (continued) |
| Pin produk 16 | PGND — Power ground (continued) |
Aplikasi Umum
LT8609SIV#PBF cocok untuk 6 aplikasis: Automotive Always-On Power Supply, Industrial 24 V Sensor and Actuator Rails, Battery-Powered Portable Instruments, General-Purpose 5 V / 3.3 V / 1.8 V Point-of-Load Conversion, Telecom and Networking Equipment Rails, Solar and Energy-Harvested Systems.
Automotive Always-On Power Supply
The LT8609SIV#PBF's 1.7 µA non-switching quiescent current and 42 V input tolerance make it ideal for automotive always-on systems that remain active when the ignition is off, such as body control modules and CAN transceivers. The part survives 12 V battery cold-crank (down to 3.0 V) and 24 V load-dump transients up to 42 V without external protection. Its 2 A continuous / 3 A peak output supports wake-up transients for downstream MCUs and sensors while drawing only microamps in standby, directly extending battery life for vehicles parked for weeks at a time.
Direkomendasikan
Industrial 24 V Sensor and Actuator Rails
Industrial 24 V bus systems benefit from the LT8609SIV#PBF's wide 3.0 V to 42 V input range, which accommodates typical 24 V nominal rails with substantial transient margin. The 2 A continuous output can drive multiple 24 V-to-3.3 V/5 V sensor nodes or a single high-current actuator driver stage from a compact TFQFN-16 footprint. The 2 MHz programmable switching frequency allows designers to place the switching frequency above the AM band or synchronize to a system clock to avoid interference with nearby analog sensor front ends.
Direkomendasikan
Battery-Powered Portable Instruments
The LT8609SIV#PBF's 1.7 µA quiescent current is the headline feature for battery-powered portable instruments such as handheld multimeters, portable gas detectors, and field data loggers. The wide input range (3.0 V to 42 V) allows direct operation from a multi-cell lithium pack, a 9 V battery, or even an unregulated solar/battery-harvested supply. The 2 A continuous output is more than sufficient for MCUs, BLE radios, and small displays, while the 2 MHz switching frequency keeps the external inductor small enough for handheld form factors.
Direkomendasikan
General-Purpose 5 V / 3.3 V / 1.8 V Point-of-Load Conversion
The LT8609SIV#PBF serves as a versatile point-of-load (POL) converter in distributed power architectures, stepping down 12 V or 24 V intermediate buses to local 5 V, 3.3 V, or 1.8 V rails for MCUs, SoCs, and FPGAs. The 0.782 V minimum reference allows direct generation of 1.0 V and 0.85 V core voltages for low-power processors. With synchronous internal MOSFETs, designers avoid an external Schottky diode, reducing both BOM count and PCB area in dense digital designs where each square millimeter counts.
Direkomendasikan
Telecom and Networking Equipment Rails
In telecom and networking line cards, the LT8609SIV#PBF's 42 V input range covers -48 V telecom bus systems after a downstream hot-swap or front-end converter provides a 12 V or 24 V intermediate rail. The 1.7 µA IQ supports sleep-mode efficiency requirements, while the 2 A continuous output handles PHY, MAC, and small FPGA rails. The exposed-pad TFQFN-16 footprint supports reflow soldering compatible with standard telecom PCB assembly processes.
Direkomendasikan
Solar and Energy-Harvested Systems
Energy-harvested systems that operate from small solar panels or thermoelectric generators benefit from the LT8609SIV#PBF's 1.7 µA quiescent current, which minimizes standby losses and allows the system to operate from the harvester's residual energy. The 3.0 V minimum input supports direct operation from a single-cell Li-ion or a low-voltage harvester, while the 42 V maximum protects against open-circuit panel transients. The high switching frequency allows a small inductor that fits in harvester nodes with strict size constraints.
Direkomendasikan
Ringkasan Produk Direkomendasikan
Data referensi engineering untuk LT8609SIV#PBF — pembandingan, panduan desain, dan informasi konformitas.
Panduan Pemilihan
Pembandingan dengan Alternatif
| Parameter Umum | Produk Ini | LT8609SEV#PBF | LT8609SIV#WPBF | LT8609SIV#TRPBF |
|---|---|---|---|---|
| Package | 16-TFQFN Exposed Pad | 16-TFQFN Exposed Pad - same | 16-TFQFN Exposed Pad - same | 16-TFQFN Exposed Pad - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Input Voltage Range | 3.0 V to 42 V | 3.0 V to 42 V | 3.0 V to 42 V | 3.0 V to 42 V |
| Continuous Output Current | 2 A | 2 A | 2 A | 2 A |
| Peak Output Current | 3 A (<1 sec) | 3 A (<1 sec) | 3 A (<1 sec) | 3 A (<1 sec) |
| Non-Switching Quiescent Current | 1.7 µA | 1.7 µA | 1.7 µA | 1.7 µA |
| Minimum Output Voltage | 0.782 V | 0.782 V | 0.782 V | 0.782 V |
| Operating Junction Temperature | -40 °C to +125 °C | 0 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C |
Diferensiator Kunci
- Industrial temperature grade (-40 °C to +125 °C) (vsLT8609SEV#PBF)
- Identical electrical performance across packaging codes (vsLT8609SIV#WPBF / LT8609SIV#TRPBF)
Catatan Desain
Place the input bypass capacitor as close as possible to the IN and PGND pins of the LT8609SIV#PBF to minimize the high-frequency switching loop area. Use a 1 µF or 2.2 µF X7R ceramic with low ESR, and pair it with a larger 10 µF or 22 µF bulk capacitor to handle input current ripple. The exposed pad must be soldered to a continuous PGND copper pour that covers at least 1 square inch on the top and inner layers to provide a low-thermal-impedance path for sustained 2 A operation.
Estimated: at VIN = 12 V, VOUT = 5 V, IOUT = 2 A, the LT8609SIV#PBF dissipates approximately (12 - 5) V × 2 A × (1 - efficiency) W; assuming 90% efficiency this is roughly 1.6 W. The TFQFN-16 package typically has theta_JA around 35 °C/W on a 1 sq inch 4-layer PCB, resulting in approximately 56 °C junction temperature rise above ambient. For continuous 2 A operation at higher VIN/VOUT differentials, additional copper area or airflow may be required to keep the junction below the 125 °C maximum.
Do not exceed 42 V at the IN pin, even transiently, as this can damage the internal MOSFETs. Place the BST capacitor as close to the BST and SW pins as possible; a missing or poorly placed bootstrap capacitor will cause the high-side FET to fail to enhance, leading to poor efficiency or destruction. Use a feedforward capacitor (CFF) of around 10 pF to 100 pF in parallel with the upper feedback resistor when the output is well above the 0.782 V reference, to compensate the loop and improve transient response.
Informasi Konformitas
RoHS compliant per PBF suffix. Not AEC-Q100 qualified; for AEC-Q100 automotive grade, contact Analog Devices about automotive-qualified variants.
