LT3599 4-Channel Automotive LED Driver IC - 120mA per String, Boost Converter, True Color PWM Dimming

LT3599 is a fixed frequency 2A step-up DC/DC converter specifically designed to drive up to four strings of LEDs at 120mA per string, with an output voltage capability up to 44V.

This IC is an ideal power solution for automotive instrument cluster displays and TFT LCD backlighting applications.
It integrates a high-efficiency boost topology that maintains accurate LED current regulation even when the input voltage exceeds the LED output voltage.

The switching frequency is programmable from 200kHz to 2.1MHz through an external resistor, allowing designers to optimize for efficiency or component size.

For brightness control, the device supports two dimming methods.
Analog dimming via the CTRL pin provides up to 20:1 dimming range.
Pulse width modulation dimming on the PWM pin delivers a True Color PWM dimming ratio of up to 3000:1, ensuring consistent color temperature across all brightness levels.

Current matching accuracy is a key strength of this chip, achieving ±1.5% matching between LED strings to guarantee uniform display brightness.

Robust protection features are built into the silicon.
These include open LED detection with the OPENLED fault flag, short LED protection with SHORTLED alert pins, and programmable overvoltage protection.
The device also offers programmable LED current derating and soft-start functionality.

Additional features include synchronization capability to an external clock, programmable input undervoltage lockout with hysteresis, and a shutdown mode that disconnects LEDs to minimize current consumption.

The LT3599 is available in thermally enhanced 32-pin QFN (5mm x 5mm) and 28-pin TSSOP packages, making it suitable for space-constrained automotive ECU designs.
It operates over an extended automotive temperature range, ensuring reliable performance in harsh under-dash and instrument panel environments.