TI TPS92691精密PWM调光汽车照明LED驱动参考设计

发布时间：2017-02-28 09:12:00点击：144评论：0字体：T|T

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2V到65V,在25℃ - 140℃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(ACTIVE) TIDA-01183 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℃ to 140℃ 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 across the high impedance analog adjust (IADJ) input. PWM dimming of LED current is achieved by modulating the PWM input pin with the desired duty cycle and frequency. Optional DDRV gate driver output can be used to enable series FET dimming functionality to get over 1000:1 contrast ratio.

The TPS92691/-Q1 supports continuous LED status check through the current monitor (IMON) output. This allows for LED short circuit or open circuit detection and protection. Additional fault protection features include VCC UVLO, output OVP, switch cycle-by-cycle current limit, and thermal protection.

TPS92691/-Q1主要特性:

Wide Input Voltage: 4.5 V to 65 V
Wide Output Voltage Range: 2 V to 65 V
Low Input Offset Rail-to-Rail Current Sense Amplifier
Better than ±3% LED Current Accuracy over 25℃ to 140℃ Junction Temperature Range
Compatible With High-Side and Low-Side Current Sense Implementations
High-Impedance Analog LED Current Adjust Input (IADJ) With over 15:1 Contrast Ratio
Over 1000:1 Series FET PWM Dimming Ratio With Integrated Series N-Channel Dim Driver Interface
Continuous LED Current Monitor Output for System Fault Detection and Diagnoses
Programmable Switching Frequency With External Clock Synchronization Capability
Programmable Soft-Start and Slope Compensation
Comprehensive Fault Protection Circuitry Including VCC Undervoltage Lockout (UVLO), Output Overvoltage Protection (OVP), Cycle-by-Cycle Switch Current Limit, and Thermal Protection
TPS92691-Q1: Automotive Q100 Grade 1 Qualified

TPS92691/-Q1应用:

Exit, Emergency Lighting
Exterior Lighting - Headlight