LT3791HFE

LED Driver IC Overview

The LT3791HFE is a synchronous, four-switch buck-boost LED driver controller manufactured by Analog Devices. It regulates LED current for strings with voltages up to 52V, regardless of whether the input voltage is higher, lower, or equal to the output. The device operates within an input voltage range of 4.7V to 60V and supports a switching frequency between 200kHz and 700kHz. It features a low operating supply current of 3mA and is housed in a 38-pin TSSOP-EP package. The controller includes clock synchronization capabilities and supports analog and PWM dimming functions.

LED Driver IC Feature Summary

• Synchronous four-switch buck-boost topology enables regulation when input voltage exceeds, falls below, or equals the LED string voltage
• Integrated clock synchronization allows operation in multi-source systems to minimize noise interference
• Supports both analog and PWM dimming methods for precise light control

LED Driver IC Applications

• High-power LED lighting systems requiring wide input voltage ranges
• Automotive exterior lighting applications
• Industrial lighting fixtures
• Portable battery-powered LED drivers

LED Driver IC Procurement Notes

Verify the specific suffix (e.g., HFE vs. HFE-1) against the official datasheet to ensure correct pinout and electrical specifications. Confirm RoHS compliance status and packaging type (tube or tape/reel) as required by your assembly process. Cross-reference the manufacturer part number with authorized distributors to avoid counterfeit components.

LED Driver IC Selection Notes

Select this component when designing LED drivers that must handle significant variations between source voltage and load voltage without reversing polarity. Ensure the external MOSFETs selected can handle the peak currents associated with the desired output power. Verify that the chosen switching frequency aligns with the thermal design and electromagnetic interference requirements of the final application.

LED Driver IC Part Context

The LT3791 belongs to a family of high-voltage synchronous buck-boost controllers designed primarily for LED driving. It distinguishes itself from standard buck or boost converters by managing energy transfer in all four quadrants of operation relative to the input-output voltage relationship. This makes it suitable for applications where the power source voltage is unstable or significantly different from the LED forward voltage.

LED Driver IC Replacement Considerations

Direct replacements may include other Analog Devices synchronous buck-boost LED controllers such as the LT3791HFE#TRPBF for tape-and-reel packaging. Check for equivalent functionality in terms of maximum input voltage, switch current limits, and package dimensions before substituting.