Linear LTC3775高效降压DC转换方案

Linear 公司的LTC3775是高效同步降压DC/DC控制器,输入电压从4.5V到38V,开关频率从250kHz 到1MHz,输出电压从0.6V 到 0.8VIN,主要应用在汽车电子系数,通信和工业设备电源以及点负载.本文介绍了LTC3775主要特性,方框图, 典型应用电路,包括5-26V输入,1.2V/12A输出; 8-36V输入,2.52V/10A输出和24V输入,12V/5A输出电路图.

The LTC3775 is a high efficiency synchronous step-down switching DC/DC controller that drives an all N-channel power MOSFET stage from a 4.5V to 38V input supply voltage. A patented line feedforward compensation circuit and a high bandwidth error amplifier provide very fast line and load transient response.

High step-down ratios are made possible by a low 30ns minimum on-time, allowing extremely low duty cycles MOSFET RDS(ON) current sensing maximizes efficiency.

Alternatively, a sense resistor can be used for higher current limit accuracy. Continuous monitoring of the voltages across the top and bottom MOSFETs allows cycle-by-cycle control of the inductor current, configurable by external resistors.

The soft-start function controls the duty cycle during start-up, providing a smooth output voltage ramp up. The operating frequency is user programmable from 250kHz to 1MHz and can be synchronized to an external clock.

LTC3775主要特性:
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