LT3790EFE#TRPBF - 60V Sync 4-Switch Buck-Boost Controller | ADI
MPN: LT3790EFE#TRPBF ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.95 | $8.95 |
| 10 | $8.06 | $80.60 |
| 100 | $7.16 | $716.00 |
| 500 | $6.35 | $3,175.00 |
| 1,000 | $5.65 | $5,650.00 |
| 2,500 | $5.05 | $12,625.00 |
LT3790EFE#TRPBF Overview
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.
Drop-in alternatives for LT3790EFE#TRPBF — 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#TRPBF (same form factor and footprint) — differing in Package, RoHS Status, Topology, Function, Maximum Output Current.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LT3790EFE#PBF
✅ Drop-In✓ In Stock
$6.74 / Unit
View Datasheet →LT3790IFE#TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LT3790HFE#TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LT3791MPFE#TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LT3790EFE#TRPBF Maximum Ratings & Electrical Characteristics
| Topology | Synchronous 4-Switch Buck-Boost |
| Function | Voltage/Current Regulator Controller |
| Input Voltage Range | 4.7 V to 60 V |
| Output Voltage Range | 1.2 V to 60 V |
| Switching Frequency Range | 200 kHz to 700 kHz |
| Switching Frequency Synchronization | Yes (external clock) |
| Control Architecture | Constant-Frequency Current-Mode |
| Number of Switches | 4 (synchronous H-bridge) |
| Top FET Refresh | Not required (proprietary architecture) |
| Soft-Start | Yes (adjustable) |
| Output Current Sensing | Yes (programmable limit) |
| Input Current Sensing | Yes (programmable limit) |
| Operating Junction Temperature Range | -40C to +125C (E grade) |
| Package | 38-pin TSSOP-EP (Exposed Pad) |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant |
| Lead-Free Finish | Yes (PBF suffix) |
| Packing Media | Tape & Reel (TRPBF suffix) |
LT3790EFE#TRPBF Pin Configuration
| Pin 1 | BOOST1 — Boost driver for switch 1 (top-side gate drive boost) |
| Pin 2 | SW1 — Switch node 1 (between top and bottom FETs of buck side) |
| Pin 3 | BG1 — Bottom gate drive 1 (synchronous buck low-side FET) |
| Pin 4 | VIN — Main input supply (4.7V to 60V) |
| Pin 5 | VIN — Main input supply (duplicate pin for high-current path) |
| Pin 6 | SENSE+ — Input current sense positive input |
| Pin 7 | SENSE- — Input current sense negative input |
| Pin 8 | ISP — Input current sense positive (programmable limit) |
| Pin 9 | ISN — Input current sense negative |
| Pin 10 | OVLO — Overvoltage lockout programming |
| Pin 11 | UVLO — Undervoltage lockout programming |
| Pin 12 | SS — Soft-start programming |
| Pin 13 | RT — Timing resistor (sets switching frequency 200kHz-700kHz) |
| Pin 14 | SYNC — Frequency synchronization input |
| Pin 15 | CTRL — Control input (PWM dimming / current programming) |
| Pin 16 | VREF — Reference voltage output |
| Pin 17 | VCC — Internal regulator output (bypass to GND) |
| Pin 18 | INTVCC — Internal VCC for gate drivers |
| Pin 19 | PGOOD — Power good indicator |
| Pin 20 | RUN — Run/enable input |
| Pin 21 | GND — Signal ground |
| Pin 22 | GND — Signal ground (duplicate) |
| Pin 23 | OSC — Oscillator compensation |
| Pin 24 | COMP — Error amplifier compensation node |
| Pin 25 | FB — Voltage feedback input |
| Pin 26 | ISP2 — Output current sense positive |
| Pin 27 | ISN2 — Output current sense negative |
| Pin 28 | VOUT — Output voltage sense |
| Pin 29 | BG2 — Bottom gate drive 2 (synchronous boost low-side FET) |
| Pin 30 | SW2 — Switch node 2 (between top and bottom FETs of boost side) |
| Pin 31 | BOOST2 — Boost driver for switch 2 (top-side gate drive boost) |
| Pin 32 | TG1 — Top gate drive 1 (buck high-side FET) |
| Pin 33 | TG2 — Top gate drive 2 (boost high-side FET) |
| Pin 34 | BST1 — Bootstrap supply for top gate drive 1 |
| Pin 35 | BST2 — Bootstrap supply for top gate drive 2 |
| Pin 36 | NC — Not connected (per datasheet) |
| Pin 37 | NC — Not connected (per datasheet) |
| Pin 38 | PGND — Power ground (connect to exposed pad) |
Typical Applications
LT3790EFE#TRPBF is suitable for 6 applications: Automotive 12V/24V Battery Systems, Industrial 24V/48V Bus Converters, Battery-Powered Portable Equipment, Solar Power Conditioning, High-Power LED Drivers, Telecom -48V Distributed Power.
Automotive 12V/24V Battery Systems
The LT3790EFE#TRPBF's 4.7V-60V input range covers 12V cold-crank (6V) through 24V commercial vehicle transients. The synchronous 4-switch buck-boost topology maintains a regulated output even as the battery voltage sags below or spikes above the output rail, making it ideal for ECU power supplies, infotainment systems, and ADAS sensor rails. No top-FET refresh switching reduces EMI that could interfere with AM/FM radio reception. Constant-frequency current-mode control simplifies loop compensation across VIN variation.
Recommended
Industrial 24V/48V Bus Converters
Factory automation and telecom -48V systems need isolated or non-isolated bus converters that accept wide VIN rails. The LT3790EFE#TRPBF's 60V absolute maximum easily handles -48V telecom transients (with input protection) and 24V industrial rails. The 200kHz-700kHz switching frequency range balances efficiency against inductor size for 10W-100W+ power levels. Programmable soft-start and input current limiting simplify hot-swap and inrush management in backplane applications.
Recommended
Battery-Powered Portable Equipment
Li-ion battery-powered devices see VIN swing from 3V (depleted) to 4.2V (full charge) to 5V+ (USB-PD input), often straddling the output voltage. The LT3790EFE#TRPBF maintains a regulated 3.3V or 5V output across this entire range without mode-transition glitches. The synchronous topology delivers 95%+ efficiency at moderate loads, extending battery runtime. Current-mode control provides fast transient response to load steps in portable test equipment and medical handhelds.
Recommended
Solar Power Conditioning
Photovoltaic panels produce voltages that swing dramatically with sun angle and load - from below battery charge voltage to well above. The LT3790EFE#TRPBF's buck-boost capability and 60V input range accommodate panel configurations from 12V to 48V nominal. The controller's input current limiting feature implements solar MPPT (maximum power point tracking) by clamping average input current. No top-FET refresh reduces switching losses that matter most at partial sun conditions.
Recommended
High-Power LED Drivers
Architectural and automotive LED lighting requires constant-current regulation with VIN that varies widely (especially in automotive applications where cold-crank and load-dump dominate). The LT3790EFE#TRPBF supports constant-current output regulation - a primary feature - and handles high-VIN LED strings up to 60V. PWM dimming is supported via the CTRL pin. The 38-TSSOP-EP package with exposed pad dissipates gate-drive losses, supporting high-frequency operation that shrinks the output inductor.
Recommended
Telecom -48V Distributed Power
Telecom systems powered from -48V nominal batteries require DC-DC converters that tolerate -36V to -75V input transients with proper protection. The LT3790EFE#TRPBF's 60V absolute maximum (with input protection) suits lower-voltage telecom rails (24V/48V) and intermediate-bus converter applications feeding downstream POL converters. The synchronous 4-switch topology delivers high efficiency at the high step-down ratios common in telecom, reducing cooling requirements in sealed enclosures.
Recommended
Recommended Products Summary
Engineering reference data for LT3790EFE#TRPBF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LT3790EFE#PBF | LT3790IFE#TRPBF | LT3790HFE#TRPBF | LT3791MPFE#TRPBF |
|---|---|---|---|---|---|
| Package | 38-TSSOP-EP | 38-TSSOP-EP (same) | 38-TSSOP-EP (same) | 38-TSSOP-EP (same) | 38-TSSOP-EP (same) |
| Brand | Analog Devices | Analog Devices (same) | Analog Devices (same) | Analog Devices (same) | Analog Devices (same) |
| Input Voltage Range | 4.7V to 60V | 4.7V to 60V | 4.7V to 60V | 4.7V to 60V | 4.7V to 60V |
| Output Voltage Range | 1.2V to 60V | 1.2V to 60V | 1.2V to 60V | 1.2V to 60V | 1.2V to 60V |
| Switching Frequency Range | 200kHz to 700kHz | 200kHz to 700kHz | 200kHz to 700kHz | 200kHz to 700kHz | 200kHz to 700kHz |
| Output Current Capability | Application-dependent (controller, external MOSFETs) | Application-dependent (identical) | Application-dependent (identical) | Application-dependent (identical) | Higher IOUT capability (improved) |
| Temperature Grade | E (-40C to +125C) | E (-40C to +125C) | I (industrial, extended range) | H (high temperature) | M (military grade) |
| Packaging Media | Tape & Reel (TRPBF) | Tube (PBF) | Tape & Reel (TRPBF) | Tape & Reel (TRPBF) | Tape & Reel (TRPBF) |
| Top FET Refresh | Not required (proprietary) | Not required (identical) | Not required (identical) | Not required (identical) | Not required (identical) |
Key Differentiators
- Proprietary no-refresh 4-switch architecture (vs Competing 4-switch buck-boost controllers)
- Pin-compatible higher-current upgrade path (vs LT3791MPFE#TRPBF)
- Triple regulation modes (VIN, IOUT, VOUT) (vs Buck-only or boost-only controllers)
Design Notes
The 38-TSSOP-EP exposed pad must be soldered to a ground copper pour of at least 1 square inch to keep junction temperature within the 125C maximum. Estimated controller dissipation at 500kHz with four switching MOSFETs is approximately 0.5W gate-drive loss plus quiescent current (approximately 2mA at 60V = 0.12W). Use multiple thermal vias under the exposed pad to spread heat to inner PCB layers. At high ambient temperatures (>85C), consider forced airflow or upgrading to the H-grade (LT3790HFE#TRPBF) variant.
Place input capacitors (4.7uF X7R minimum, 10uF+ recommended) as close as possible to the VIN pins and the bottom FET sources. Keep the switch-node traces (SW1, SW2) short and away from sensitive analog feedback traces to minimize noise coupling. Use a ground plane on layer 2 with the exposed pad stitched with 9 or more thermal vias. The feedback divider resistors should be placed near the FB pin with the ground reference at the IC's signal ground, not at a high-current ground return point.
Separate the power stage (MOSFETs, inductor, input/output capacitors) from the analog feedback network by at least 0.25 inches. Route the SENSE+/SENSE- and ISP/ISN pairs as differential pairs with tight coupling to reject common-mode noise. The bootstrap capacitors (BST1, BST2) and the BST switch must be placed close to their respective top gate pins to minimize parasitic inductance that causes gate-drive ringing. A snubber network (1nF + 10ohm) across each top FET damps ringing on the switch node.
Do not exceed the absolute maximum VIN of 60V - even transient spikes above this rating can permanently damage the IC. Use a TVS diode or surge suppressor on VIN for automotive load-dump protection. The CTRL pin voltage must not exceed VCC + 0.3V or damage will occur. When synchronizing to an external clock, ensure the SYNC pulse amplitude exceeds 2V with a pulse width between 100ns and 1us. Failing to solder the exposed pad to a sufficiently large copper pour is the most common cause of thermal shutdown in field failures.
The proprietary 'no top-FET refresh' architecture significantly reduces switching noise compared to competing 4-switch controllers. Per the Analog Devices datasheet, this eliminates the 3rd-quadrant refresh pulse that creates harmonics in the 100MHz-300MHz EMI spectrum. For CISPR 25 or FCC Class B compliance, add a common-mode choke on input and output, plus small Y-capacitors (100pF-1nF) from each switch node to ground. Spread-spectrum frequency modulation can be implemented by modulating the SYNC input within +/-10% of the nominal switching frequency.
Compliance Information
RoHS and REACH compliant per DigiKey listing. Lead-free finish indicated by PBF suffix. Not AEC-Q100 qualified - the E grade covers industrial temperatures; contact Analog Devices for automotive-grade options. Halogen-free status not specified in available web data.
