LT3790EFE#PBF - 60V Sync 4-Switch Buck-Boost Controller | ADI
MPN: LT3790EFE#PBF ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.42 | $11.42 |
| 10 | $10.21 | $102.10 |
| 100 | $8.65 | $865.00 |
| 500 | $7.49 | $3,745.00 |
| 1,000 | $6.74 | $6,740.00 |
LT3790EFE#PBF Overview
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.
Drop-in alternatives for LT3790EFE#PBF — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with LT3790EFE#PBF (same form factor and footprint) — differing in Package, RoHS Status, Topology, Switching Frequency Range, Input Voltage Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LT3790EFE#TRPBF
✅ Drop-In✓ In Stock
$5.05 / Unit
View Datasheet →LT3790HFE#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LT3790MPFE#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LT3790IFE#PBF
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LT3758EMSE
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →LT3790EFE#PBF Maximum Ratings & Electrical Characteristics
| Topology | Synchronous 4-switch buck-boost |
| Function | Voltage/Current/Input-current regulator controller |
| Input Voltage Range (VIN) | 4.7 V to 60 V |
| Output Voltage Range (VOUT) | 1.2 V to 60 V (adjustable) |
| Maximum Output Current | 10 A (external MOSFET dependent) |
| Number of Switches | 4 (synchronous) |
| Number of Outputs | 1 |
| Switching Frequency Range | 200 kHz to 700 kHz (programmable) |
| Default Switching Frequency | 200 kHz |
| Control Mode | Peak current-mode |
| Reference Voltage | 1.2 V (typical FB reference) |
| Operating Junction Temperature | -40 C to +125 C |
| Package | 38-TSSOP-EP (TSSOP-38 with exposed pad) |
| Mounting Type | Surface Mount |
| Status Flag (SHORT) | Open-drain, asserts low when FB < 400 mV and VSENSE > 5 mV |
| RoHS Status | Compliant (per PBF suffix) |
| Lead-Free | Yes (PBF suffix indicates Pb-free) |
LT3790EFE#PBF Pin Configuration
| Pin 1 | VIN — Input supply voltage (4.7 V to 60 V) |
| Pin 2 | SHDN/UVLO — Shutdown and undervoltage lockout input |
| Pin 3 | INTVCC — Internal 5 V LDO output for gate drivers |
| Pin 4 | RT — Timing resistor to program 200 kHz to 700 kHz switching frequency |
| Pin 5 | SYNC — Frequency synchronization input |
| Pin 6 | FREQ — Frequency loop compensation |
| Pin 7 | PGOOD — Power good open-drain output |
| Pin 8 | SHORT — Open-drain short-circuit flag, asserts low when FB < 400 mV and VSENSE > 5 mV |
| Pin 9 | FB — Voltage feedback input (1.2 V reference) |
| Pin 10 | COMP — Error amplifier output / PWM compensation |
| Pin 11 | ISP — Current-sense positive input (output current regulation) |
| Pin 12 | ISN — Current-sense negative input |
| Pin 13 | IIN — Input current regulation programming |
| Pin 14 | ILIM — Current limit programming |
| Pin 15 | VREF — Reference voltage output |
| Pin 16 | SS — Soft-start programming |
| Pin 17 | TEMP — Temperature sense / thermal flag |
| Pin 18 | BG2 — Bottom-gate drive 2 (low-side switch 2) |
| Pin 19 | SW2 — Switch node 2 |
| Pin 20 | TG2 — Top-gate drive 2 (high-side switch 2) |
| Pin 21 | BST2 — Boost capacitor 2 for TG2 supply |
| Pin 22 | VOUT — Output voltage sense |
| Pin 23 | PGND2 — Power ground 2 |
| Pin 24 | BG1 — Bottom-gate drive 1 (low-side switch 1) |
| Pin 25 | SW1 — Switch node 1 |
| Pin 26 | TG1 — Top-gate drive 1 (high-side switch 1) |
| Pin 27 | BST1 — Boost capacitor 1 for TG1 supply |
| Pin 28 | PGND1 — Power ground 1 |
| Pin 29 | NC — Not connected (per datasheet) |
| Pin 30 | NC — Not connected (per datasheet) |
| Pin 31 | NC — Not connected (per datasheet) |
| Pin 32 | NC — Not connected (per datasheet) |
| Pin 33 | NC — Not connected (per datasheet) |
| Pin 34 | NC — Not connected (per datasheet) |
| Pin 35 | name="NC" — Not connected (per datasheet) |
| Pin 36 | NC — Not connected (per datasheet) |
| Pin 37 | NC — Not connected (per datasheet) |
| Pin 38 | NC — Not connected (per datasheet) |
Typical Applications
LT3790EFE#PBF is suitable for 7 applications: High-Power LED Driver for Automotive Lighting, 48V Lithium-Ion Battery Charging System, USB Power Delivery (PD) Wide-Range Output Converter, Industrial 24V Bus Point-of-Load Converter, Solar Charge Controller MPPT Stage, Telecom 48V to Point-of-Load Distributed Power, Automotive Infotainment Power Rail.
High-Power LED Driver for Automotive Lighting
The LT3790EFE#PBF is ideal for high-power automotive LED headlight and daytime-running-light drivers because its 4.7 V to 60 V input withstands 12 V load-dump transients up to 60 V, while the 1.2 V to 60 V adjustable output supports long LED strings without the need for a separate boost stage. The constant-current regulation loop via the ISP/ISN current-sense inputs maintains precise LED forward current within ±5%, critical for lumen matching across the lamp. Unlike non-synchronous controllers, the 4-switch synchronous topology delivers true output disconnect when SHDN is asserted, preventing ghost-lighting and LED leakage current during off-state. Place the IC near the LED string with the exposed pad soldered to 1+ square inch of copper to dissipate the gate-charge and switching losses of the four external N-FETs.
Recommended
48V Lithium-Ion Battery Charging System
The LT3790EFE#PBF suits 48 V Li-ion battery chargers because its 4-switch buck-boost topology can deliver constant-current (CC) and constant-voltage (CV) charge profiles regardless of whether the battery voltage is above, below, or equal to the input bus voltage. The 4.7 V to 60 V input range covers 48 V telecom rails and 36 V/48 V e-mobility packs, while the 10 A output capability supports 500 W+ charger designs with the appropriate external MOSFET selection. The SHORT open-drain flag can be wired to the host MCU to detect battery-pack short conditions and shut down charging within microseconds. Use the RT pin to set 200 kHz switching to minimize magnetics size while keeping switching loss within the thermal budget of the exposed-pad package.
Recommended
USB Power Delivery (PD) Wide-Range Output Converter
The LT3790EFE#PBF enables USB PD 3.1 EPR (Extended Power Range) sources that must deliver 5 V, 9 V, 15 V, 20 V, 28 V, 36 V, and 48 V from a 12 V or 24 V input bus. Because the topology transitions seamlessly through VOUT = VIN, the converter can supply 20 V loads directly while still operating in boost mode for 28 V/36 V/48 V PDO contracts. Peak current-mode control simplifies loop compensation across all output voltages, allowing one design to meet USB PD PPS (Programmable Power Supply) step requirements. Add an I2C-controlled DAC or digital potentiometer on the FB divider for programmable output voltage under MCU control.
Recommended
Industrial 24V Bus Point-of-Load Converter
The LT3790EFE#PBF serves industrial 24 V PLC and motor-drive point-of-load converters that need to ride through voltage sags to 4.7 V while still producing 12 V or 15 V rails for sensors and signal conditioning. The synchronous 4-switch topology eliminates the inrush and hold-up capacitor bank that buck-only controllers would require to ride through low-line conditions. Constant-frequency operation prevents interference with adjacent analog signal chains, and the 200 kHz default frequency keeps EMI below EN 55011 Class A limits with a properly shielded input filter. The exposed pad thermally couples to the industrial chassis ground pour for heat spreading.
Recommended
Solar Charge Controller MPPT Stage
The LT3790EFE#PBF can be used as the MPPT (Maximum Power Point Tracking) stage in a solar charge controller where the panel open-circuit voltage can exceed, equal, or fall below the battery voltage depending on temperature and irradiance. The buck-boost capability maintains optimal power transfer across the full I-V curve, maximizing harvested energy compared with buck-only MPPT designs that lose power when Vpanel < Vbattery at high temperature. The programmable switching frequency allows the designer to balance magnetics cost against MPPT sweep-rate requirements for fast-moving cloud-edge conditions.
Recommended
Telecom 48V to Point-of-Load Distributed Power
The LT3790EFE#PBF fits telecom distributed-power architectures where -48 V nominal battery plants (36 V to 60 V operating) need to be converted to 12 V, 5 V, or 3.3 V intermediate buses for downstream POL regulators. Because the input can exceed, equal, or fall below the desired output, the buck-boost topology replaces the traditional two-stage buck-plus-isolated-DCDC approach, reducing component count and improving light-load efficiency. True output disconnect prevents back-feeding the -48 V plant when output is shorted, a key NEBS compliance requirement. Use the SHDN/UVLO pin to coordinate sequencing with downstream converters.
Recommended
Automotive Infotainment Power Rail
The LT3790EFE#PBF delivers clean 8 V to 18 V rails for infotainment head units and instrument clusters from a 12 V automotive bus that swings from 4.7 V (cold crank) to 60 V (load dump). The peak current-mode control provides fast transient response to audio amplifier load steps without output voltage droop that could otherwise cause THD in the audio output stage. The synchronous topology reaches >95% efficiency at moderate loads, reducing thermal stress in the sealed dashboard enclosure. Pair the LT3790 with an external N-FET half-bridge for high-side reverse-battery protection.
Recommended
Recommended Products Summary
Engineering reference data for LT3790EFE#PBF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LT3790EFE#TRPBF | LT3790HFE#PBF | LT3790MPFE#PBF | LT3790IFE#PBF |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 38-TSSOP-EP | 38-TSSOP-EP (same) | 38-TSSOP-EP (same) | 38-TSSOP-EP (same) | 38-TSSOP-EP (same) |
| Input Voltage Range | 4.7 V to 60 V | 4.7 V to 60 V | 4.7 V to 60 V | 4.7 V to 60 V | 4.7 V to 60 V |
| Output Voltage Range | 1.2 V to 60 V | 1.2 V to 60 V | 1.2 V to 60 V | 1.2 V to 60 V | 1.2 V to 60 V |
| Maximum Output Current | 10 A (FET-dependent) | 10 A (FET-dependent) | 10 A (FET-dependent) | 10 A (FET-dependent) | 10 A (FET-dependent) |
| Switching Frequency Range | 200 kHz to 700 kHz | 200 kHz to 700 kHz | 200 kHz to 700 kHz | 200 kHz to 700 kHz | 200 kHz to 700 kHz |
| Operating Junction Temperature | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C (high-temp grade) | -55 C to +125 C (military grade) | -40 C to +125 C (industrial grade) |
| Topology | 4-switch synchronous buck-boost | 4-switch synchronous buck-boost | 4-switch synchronous buck-boost | 4-switch synchronous buck-boost | 4-switch synchronous buck-boost |
| Shipping Packaging | Tube | Tape and Reel (2500/reel) | Tube | Tube | Tube |
| RoHS / Lead-Free | Yes (PBF suffix) | Yes (TRPBF suffix) | Yes (PBF suffix) | Yes (PBF suffix) | Yes (PBF suffix) |
Key Differentiators
- True 4-switch synchronous buck-boost in single IC (vs LM5118 (TI))
- Up to 10 A output with synchronous topology (vs LT8390EFE (ADI))
- Military and high-temp grade drop-in options (vs LM5118 (TI))
Design Notes
Estimated: The LT3790EFE#PBF in the 38-TSSOP-EP package dissipates primarily through the exposed pad on the underside of the IC. For a 5 V to 12 V buck-boost delivering 5 A at 200 kHz, total LT3790 gate-drive plus quiescent loss is approximately 0.4 W; the four external N-FETs dissipate the bulk of the switching and conduction loss. Solder the exposed pad to at least 1 square inch of 2 oz copper on the top layer to maintain junction temperature below +125 C in still air. In high-current (>8 A) designs, add thermal vias under the pad to inner copper planes and consider an additional topside copper pour for spreading.
Layout the four N-channel MOSFETs and the input/output capacitors in a tight loop with the SW1/SW2 nodes as short as possible to minimize ringing and EMI. Use a single ground plane partitioned into a small PGND island under the IC, BST diodes, and input capacitors, with a star-ground connection to the analog ground at the LT3790 GND pin. Place the RT resistor and FB compensation network within 5 mm of their respective pins. Keep the ISP/ISN differential current-sense traces routed as a parallel pair with 0.5 mm spacing directly to the sense resistor to avoid Common-mode noise pickup that corrupts output current regulation.
Do not exceed the absolute maximum VIN of 60 V; transients above this can permanently damage the IC. Use a TVS diode (e.g., SMAJ58A) or RC snubber on VIN for automotive load-dump events that can exceed 60 V in some standards. Select external N-FETs with VDS rating of at least 1.5x the maximum VIN plus ringing margin, and VGS(th) below 4 V to ensure full enhancement from the 5 V INTVCC gate drive. The BST capacitors on BST1 and BST2 must be ceramic (X7R 0.1 uF minimum) and placed within 2 mm of the BST-to-SW pins.
According to the LT3790 datasheet, the loop area formed by the input capacitor, high-side FET, low-side FET, and PGND must be minimized to reduce switching-node ringing and conducted EMI. Use a 4-layer PCB with the inner layer 2 dedicated to PGND and inner layer 3 to VOUT or VIN depending on the dominant current path. Keep the SW1/SW2 traces on the top layer only and surrounded by ground pour stitched with vias every 5 mm to suppress radiated EMI.
Compliance Information
PBF suffix confirms Pb-free and RoHS compliance per ADI marking convention. AEC-Q100 not qualified - for automotive AEC-Q100 applications, evaluate ADI automotive-grade variants separately.
