Battery protection circuits

摘要

An overvoltage battery protection circuit includes a voltage comparator configured to compare a scaled version of a voltage with a voltage reference and indicate an overvoltage condition when the scaled voltage exceeds the voltage reference. The voltage comparator is powered by a first voltage domain. The circuit further includes a first transistor coupled to an output of the voltage comparator and configured to turn on when the voltage comparator indicates the overvoltage condition and generate an overvoltage signal for at least one external device. The circuit further includes a second transistor coupled to the overvoltage signal and configured to turn on when the overvoltage signal is asserted and force the overvoltage signal to remain asserted independent of the first voltage domain. The first and second transistors are powered by a second voltage domain.

主权项

1. An overvoltage battery protection circuit, comprising:
a voltage comparator configured to compare a scaled voltage with a reference voltage and indicate an overvoltage condition if the scaled voltage exceeds the reference voltage, wherein the voltage comparator is powered by a first voltage domain provided by a first power supply; a first transistor coupled to an output of the voltage comparator and configured to: turn on when the voltage comparator indicates the overvoltage condition, and provide an overvoltage signal; and a second transistor configured to receive the overvoltage signal, turn on when the overvoltage signal is asserted, and provide the overvoltage signal when the first transistor turns off, wherein the first transistor and the second transistor are powered by a second voltage domain provided by a second power supply different than the first power supply, and the second transistor limits the overvoltage signal when the second voltage domain reaches or falls below a threshold value.