应用于升压型DC-DC的新颖软启动电路的设计

提出了一种新颖的软启动电路,实现了输出电压无过冲平滑启动。该电路有效抑制了DC-DC开关电源上电启动过程出现的浪涌电流和输出电压的过冲,同时该软启动电路克服了传统软启动电路无法带载启动的缺点。电路完全集成在芯片内部,避免了使用额外电容而占用过多面积。利用Cadence Spectre仿真平台对电路进行了仿真验证,仿真结果表明,在输入电压为2.4~4.2 V的同步升压DC-DC芯片中,负载在0~2.1 A范围内启动,均未出现电感电流和输出电压的过冲。

Design of a Novel Soft-start Circuit Applied to Step-Up DC-DC

This paper proposes a novel soft-start circuit,which raises the output voltage from zero to regulated value smoothly.This circuit effectively suppresses the DC-DC switching power supply inrush current and output voltage overshoot during startup.At the same time,the soft-start circuit overcomes the shortcoming that the traditional soft-start circuit can not start up with heavy load.This circuit is easy to integrate into the DC-DC regulator,because we do not use the external capacitor which takes too much area.The Cadence Spectre simulation platform is used for circuit simulation and verification.In the synchronous boost DC-DC chip with an input voltage of 2.4~4.2 V,the load starts up within the range of 0~2.1 A,and neither inductor current nor output voltage overshoot appears.