一种用于低压Boost型DC-DC转换器的启动电路

Design of a low input voltage startup circuit for the Boost DC-DC converter

提出了一种适用于低输入电压Boost型DC-DC转换器的启动电路.该电路先通过开环工作使DC-DC芯片启动,再采用从输出端取电方式来提供电源让芯片正常工作,它的最小启动电压可达1.5 V,电源引脚工作电流极小.此电路已在UMC 0.6μm BCD工艺线上投片验证,测试结果表明芯片可以在大于或等于1.5 V的输入电压下进行启动并正常工作,电源引脚静态电流仅为18μA,在1.5 V转7 V的应用条件下,电感峰值电流达2 A.

This paper presents a startup circuit for a low voltage Boost DC-DC converter. Firstly, the DC-DC converter is started in the open loop, and then the converter is powered by the output port for normal operation. Secondly, the minimum voltage of the circuit is as low as 1.5 V. Thirdly, the quiescent current of the VIN Pin is small. Finally, the circuit is designed and implemented by UMC 0. 6μm BCD technology. Experimental results demonstrate that DC-DC can be started up in an input voltage greater than or equal to 1.5 V. The quiescent current of the VIN is only 18 μA. With VIN = 1. 5 V and VOUT = 7 V, the peak current of the inductor is 2 A.