Linear LT3796 100V LED控制方案

Linear公司的LT3796用來驅動LED的可調(diào)整恒流或恒壓的DC/DC控制器,3000:1 True Color PWM?調(diào)光,輸入電壓從6V到100V,電流監(jiān)測高達100V,可調(diào)開關頻率100kHz到1MHz,雙電流檢測放大器,可編線性電流檢測閾值,短路保護,主要用在大功率LED和高壓LED,電池和超級電容充電以及精密的限流電壓穩(wěn)壓器.本文介紹了LT3796主要特性,方框圖,多種應用電路以及100V評估板DC1706A主要特性,電路圖,材料清單和PCB元件布局圖.

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: