TI公司的TPS92691/-Q1是具有轨到轨电流检测放大器的多种拓扑LED驱动器,输入电压4.5 V 到 65 V,输出电压2 V 到65 V,在25°C - 140°C温度范围优于±3%的LED电流精度,可编开关频率和软起动与斜率补偿,主要用在紧急照明和外部照明如头灯.本文介绍了TPS92691/-Q1主要特性,框图和几种应用电路,以及汽车照明TIDA-01183参考设计主要特性和指标,框图,电路图,材料清单和PCB设计图.
Precision PWM Dimming LED Driver Reference Design for Automotive Lighting
The TPS92691/-Q1 is a versatile LED controller that can support a range of step-up or step-down driver topologies. The device implements a fixed-frequency peak current mode control technique with programmable switching frequency, slope compensation, and soft-start timing. It incorporates a high voltage (65-V) rail-to-rail current sense amplifier that can directly measure LED current using either a high-side or a low-side series sense resistor. The amplifier is designed to achieve low input offset voltage and attain better than ±3% LED current accuracy over junction temperature range of 25°C to 140°C and output common-mode voltage range of 0 to 60 V.
LED current can be independently modulated using either analog or PWM dimming techniques. Linear analog dimming response with 15:1 range is obtained by varying the voltage from 140 mV to 2.25 V