Linear LT3796 100V LED控制方案

Linear公司的LT3796用来驱动LED的可调整恒流或恒压的DC/DC控制器,3000:1 True Color PWM™调光,输入电压从6V到100V,电流监测高达100V,可调开关频率100kHz到1MHz,双电流检测放大器,可编线性电流检测阈值,短路保护,主要用在大功率LED和高压LED,电池和超级电容充电以及精密的限流电压稳压器.本文介绍了LT3796主要特性,方框图,多种应用电路以及100V评估板DC1706A主要特性,电路图,材料清单和PCB元件布局图.

The LT3796 is a DC/DC controller designed to regulate a constant-current or constant-voltage and is ideal for driving LEDs. It drives a low side external N-channel power MOSFET from an internal regulated 7.7V supply. The fixed frequency and current mode architecture result in stable operation over a wide range of supply and output voltages.

Two ground referred voltage FB pins serve as the input for several LED protecTIon features, and also allow the converter to operate as a constant-voltage source.

The LT3796 features a programmable threshold output sense amplifier with rail-to-rail common mode range. The LT3796 also includes a separate high side current sensing amplifier that is gain configurable with two resistors. The TG pin inverts and level shifts the PWM signal to drive the gate of the external PMOS. The PWM input provides LED dimming ratios of up to 3000:1, and the CTRL input provides addiTIonal analog dimming capability.

LT3796主要特性:

3000:1 True Color PWM™ Dimming

Wide Input Voltage Range: 6V to 100V

Current Monitoring Up to 100V

High Side PMOS Disconnect and PWM Switch Driver

Constant-Current and Constant-Voltage RegulaTIon

Dual Current Sense Amplifiers with ReporTIng

C/10 Detection for Battery and SuperCap Charging

Linear Current Sense Threshold Programming

Short-Circuit Protection

Adjustable Frequency: 100kHz to 1MHz

Frequency Synchronization

Programmable Open LED Protection with VMODE Flag

Programmable Undervoltage Lockout with Hysteresis

Soft-Start with Programmable Fault Restart Timer

Low Shutdown Current: