3 Description

The TPS925302-Q1 is a monolithic, 2-channel, synchronous, buck LED driver with a wide 4.5V to 65V operating input voltage range that can independently power two strings of series connected LEDs. The TPS925302-Q1 implements an adaptive on-time average current mode control and is designed to generate constant voltage or constant current output. The adaptive on-time control provides near constant switching frequency that can be set between 100kHz and 1.2MHz. In constant current mode, the device is compatible with shunt FET dimming techniques and with LED matrix manager-based dynamic beam headlamps. In constant voltage mode, the adaptive on-time control enables high bandwidth operation with fast transient response. Inductor current sensing and closed-loop feedback enables better than ±4% accuracy over wide input voltage, output voltage, and ambient temperature range.

In constant current mode, the high performance LED driver can independently modulate LED current using both analog or PWM dimming techniques. Linear analog dimming response with over 16:1 range is obtained by programming the 10-bit reference value (CHxREF) through SPI. PWM dimming of LED current is achieved by directly modulating the corresponding UDIM input pin with the desired duty cycle or by enabling the internal PWM generator circuit. The PWM generator translates the 10-bit PWM register value to a corresponding duty cycle by comparing value to a programmable digital counter.

The TPS925302-Q1 incorporates advanced SPI programmable diagnostic and fault protection featuring: cycle-by-cycle switch current limit, bootstrap undervoltage, LED open, LED short, thermal warning and thermal shutdown. An on-board 10-bit ADC samples critical input parameters required for system health monitoring and diagnostics.

Simplified Schematic