Overvoltage detection circuit, overcurrent detection circuit and protection detection circuit

Abstract

The invention provides an overvoltage detection circuit, an overcurrent detection circuit and a protection detection circuit, and the overvoltage detection circuit comprises a band-gap reference voltage generation circuit which is used for generating a band-gap reference voltage BG and comprises an operational amplifier OP, a first bipolar transistor Q1 and a second bipolar transistor Q2; the voltage division circuit is used for generating a first detection voltage based on the detected input voltage; the first input end of the comparator Comp1 receives the bandgap reference voltage BG, and the second input end of the comparator Comp1 receives the first detection voltage; wherein the first bipolar transistor and the second bipolar transistor are PNP bipolar transistors. Compared with the prior art, the bipolar transistor for realizing voltage detection and / or current detection can adopt a parasitic PNP type bipolar transistor in a common CMOS (Complementary Metal-Oxide-Semiconductor Transistor) process, so that photoetching steps are reduced, and the production cost of a chip is further reduced.

Description

【Technical field】 [0001] The invention relates to the field of integrated circuits, in particular to an overvoltage detection circuit, an overcurrent detection circuit and a protection detection circuit in a battery protection chip. 【Background technique】 [0002] A battery protection circuit in the prior art, such as Chinese Patent Application No. 201110229489.6, realizes the functions of voltage detection and current detection by sharing bipolar transistors. However, this implementation method requires NPN type bipolar transistors, which require a special BiCMOS process, which requires additional photolithography steps (compared to ordinary CMOS processes), resulting in increased costs (because the production cost of chips generally increases with lithography steps increase). [0003] Therefore, it is necessary to propose a new technical solution to overcome the above problems. 【Content of invention】 [0004] One of the objectives of the present invention is to provide...

AI Technical Summary

Problems solved by technology

However, this implementation method requires NPN type bipolar transistors, which require a special BiCMOS process, which requires additional photolithography steps (compared to ordinary CMOS processes), resulting in increased costs (because the production cost of chips generally increases with increased photolithography steps)

Images