LT3791EFE#PBF - 60V 4-Switch Sync Buck-Boost LED Driver | ADI
MPN: LT3791EFE#PBF β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $16.85 | $16.85 |
| 10 | $15.42 | $154.20 |
| 100 | $13.87 | $1,387.00 |
| 500 | $12.31 | $6,155.00 |
| 1,000 | $10.76 | $10,760.00 |
Drop-in alternatives for LT3791EFE#PBF β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
LT3791EFE-1#PBF
β Drop-Inπ Reference alternative (not in catalog)
LT3791IFE#PBF
β Drop-Inβ In Stock
$4.5 / Unit
View Datasheet βLT3791EFE#TRPBF
β Drop-Inβ In Stock
$5.5 / Unit
View Datasheet βLT3791IFE-1#PBF
β Drop-Inπ Reference alternative (not in catalog)
LT3791IFE-1#TRPBF
β Drop-Inπ Reference alternative (not in catalog)
LT3791EFE#PBF Maximum Ratings & Electrical Characteristics
| Topology | Buck-Boost |
| Number of Outputs | 1 |
| Output Voltage (Max) | 60 V |
| Output Current (Max) | 10 A |
| Input Voltage (Min) | 4.7 V |
| Input Voltage (Max) | 60 V |
| Switching Frequency | 200 kHz to 700 kHz |
| Dimming | Analog, PWM |
| Efficiency | 98.5% |
| Package | 38-TSSOP-EP |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +125C |
| RoHS Status | Compliant |
| Output Voltage Accuracy | 2% |
| Control Architecture | Current Mode |
LT3791EFE#PBF Pin Configuration
| Pin 1 | BOOST1 β Bootstrap for high-side MOSFET 1 |
| Pin 2 | TG1 β High-side gate drive for switch 1 |
| Pin 3 | SW1 β Switch node 1 |
| Pin 4 | BG1 β Low-side gate drive for switch 1 |
| Pin 5 | VIN β Input supply voltage |
| Pin 6 | BG2 β Low-side gate drive for switch 2 |
| Pin 7 | SW2 β Switch node 2 |
| Pin 8 | TG2 β High-side gate drive for switch 2 |
| Pin 9 | BOOST2 β Bootstrap for high-side MOSFET 2 |
| Pin 10 | VOUT β Output voltage sense |
| Pin 11 | SENSE+ β Positive current sense input |
| Pin 12 | SENSE- β Negative current sense input |
| Pin 13 | CTRL β Analog dimming control input |
| Pin 14 | PWM β PWM dimming input |
| Pin 15 | FREQ β Switching frequency set/sync |
| Pin 16 | SS β Soft-start capacitor |
| Pin 17 | VC β Error amplifier compensation |
| Pin 18 | FB β Feedback for voltage regulation |
| Pin 19 | GND β Ground |
| Pin 20 | EXPOSED PAD β Thermal pad, connect to GND |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
LT3791EFE#PBF is suitable for 6 applications: Automotive Headlamps, Industrial Lighting, High-Power LED Drivers, Battery-Powered Systems, General Lighting, LED Backlighting.
Automotive Headlamps
The LT3791EFE#PBF is ideal for automotive headlamps due to its wide input voltage range (4.7V to 60V) and high efficiency up to 98.5%. It can regulate LED current up to 10A, providing consistent brightness even as the battery voltage varies during cranking or load transients. The 4-switch buck-boost topology ensures operation when the input voltage is above or below the LED string voltage, which is common in automotive systems. PWM dimming enables adaptive lighting features, and the controller's robust protection features (open/short LED) enhance reliability in harsh environments.
Recommended
Industrial Lighting
In industrial lighting, the LT3791EFE#PBF provides a flexible solution for high-power LED drivers. Its wide input range accommodates various supply voltages (24V, 48V, etc.), and the 4-switch architecture allows driving LED strings with forward voltages above or below the input. The controller's 200kHz to 700kHz switching frequency enables optimization of inductor size and efficiency. With analog and PWM dimming, it supports precise light control for applications like street lighting and factory illumination. The high efficiency reduces thermal stress, and the 38-pin TSSOP-EP package is suitable for compact industrial fixtures.
Recommended
High-Power LED Drivers
The LT3791EFE#PBF is designed for high-power LED drivers requiring up to 10A of LED current. Its synchronous 4-switch buck-boost topology achieves up to 98.5% efficiency, minimizing power loss and heat generation. The controller regulates LED current with Β±2% accuracy, ensuring consistent light output. It supports both analog and PWM dimming, making it suitable for applications like stage lighting, architectural lighting, and LED video walls. The wide input voltage range allows operation from various power sources, including batteries and solar panels, providing design flexibility.
Recommended
Battery-Powered Systems
For battery-powered systems, the LT3791EFE#PBF's ability to operate with input voltages above, below, or equal to the output is crucial. As the battery discharges, its voltage drops, and the buck-boost topology ensures the LED current remains regulated. The controller's low quiescent current and high efficiency extend battery life. It is suitable for portable lighting, emergency lights, and solar-powered LED systems. The PWM dimming feature allows power saving by reducing brightness when full output is not needed, further enhancing battery runtime.
Recommended
General Lighting
The LT3791EFE#PBF is well-suited for general lighting applications such as LED bulbs, downlights, and panel lights. Its wide input range (4.7V to 60V) allows it to work with various AC-DC adapters or DC supplies. The high efficiency reduces energy consumption, and the compact 38-pin TSSOP-EP package enables small form factor designs. Analog dimming provides a simple interface for dimmable lighting, while PWM dimming offers high dimming ratios for advanced control. The controller's protection features ensure reliable operation in consumer lighting products.
Recommended
LED Backlighting
In LED backlighting applications, the LT3791EFE#PBF provides precise current regulation for LED strings in displays and monitors. Its 4-switch buck-boost topology allows driving LED strings with forward voltages that may be higher or lower than the input supply, which is common in backlight units. The controller supports PWM dimming for brightness control and local dimming features. With efficiency up to 98.5%, it minimizes heat generation, which is critical in thin display designs. The wide input range accommodates various power supply configurations, making it a versatile choice for backlight drivers.
Recommended
Recommended Products Summary
Engineering reference data for LT3791EFE#PBF β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LT3791EFE-1#PBF | LT3791IFE#PBF | LT3791EFE#TRPBF |
|---|---|---|---|---|
| Package | 38-TSSOP-EP | 38-TSSOP-EP | 38-TSSOP-EP | 38-TSSOP-EP |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Function | LED Driver Controller | Voltage/Current Regulator Controller | LED Driver Controller | LED Driver Controller |
| Input Voltage Range | 4.7V to 60V | 4.7V to 60V | 4.7V to 60V | 4.7V to 60V |
| Output Current | 10A | 10A | 10A | 10A |
| Switching Frequency | 200kHz to 700kHz | 200kHz to 700kHz | 200kHz to 700kHz | 200kHz to 700kHz |
| Dimming | Analog, PWM | Analog, PWM | Analog, PWM | Analog, PWM |
| Temperature Grade | Commercial (0C to 70C) | Commercial (0C to 70C) | Industrial (-40C to +125C) | Commercial (0C to 70C) |
Key Differentiators
- 4-switch synchronous buck-boost topology (vs LT3791EFE-1#PBF)
- High efficiency up to 98.5% (vs LT3791IFE#PBF)
- Wide input voltage range (4.7V to 60V) (vs LT3791EFE#TRPBF)
Design Notes
For high-current switching paths, use wide, short traces to minimize parasitic inductance and resistance. Place the input and output capacitors close to the MOSFETs and controller pins. The exposed pad should be soldered to a large copper pour for thermal dissipation. Refer to the LT3791 datasheet layout guidelines for optimal performance.
The LT3791EFE#PBF itself dissipates minimal power, but the external MOSFETs and inductor handle high currents. Ensure adequate heatsinking for the MOSFETs, especially in high-power applications. The 38-pin TSSOP-EP package's exposed pad should be connected to a ground plane to improve thermal performance. Calculate power dissipation and use thermal vias if necessary.
Avoid exceeding the absolute maximum ratings for VIN and VOUT (60V). Ensure the bootstrap capacitors are properly sized for the switching frequency. The frequency synchronization pin should be terminated if not used. Also, verify the current sense resistor value to achieve the desired LED current, as incorrect values can lead to inaccurate regulation.
Compliance Information
RoHS compliant per #PBF suffix. AEC-Q100 not applicable as this is not an automotive-qualified part.
