Battery voltage detector circuit

摘要

There is provided a battery voltage detector circuit which uses a multiplexer system and which is capable of reducing the influence of the deviation of a detected voltage attributable to a parasitic capacitance, thus improving the accuracy of voltage detection. The battery voltage detector circuit that monitors the voltages of a plurality of batteries connected in series includes a flying capacitor, a multiplexer switch that sequentially connects the flying capacitor to the plurality of batteries, a voltage detecting unit that detects the voltage of the flying capacitor, a first reference potential detecting unit connected to one terminal of the flying capacitor, a second reference potential connecting unit connected to the other terminal of the flying capacitor, and a control circuit that controls the multiplexer switch, the first reference potential connecting unit and the second reference potential connecting unit.

主权项

1. A battery voltage detector circuit adapted to monitor the voltages of a plurality of batteries connected in series, comprising:
a flying capacitor; a multiplexer switch that sequentially connects the flying capacitor to the plurality of batteries; a voltage detecting unit that detects the voltage of the flying capacitor; a first reference potential connecting unit connected to one terminal of the flying capacitor configured to generate a first current flow towards the one terminal; a second reference potential connecting unit connected to the other terminal of the flying capacitor configured to generate a second current flow towards the other terminal; and a control circuit that controls the multiplexer switch, the first reference potential connecting unit, and the second reference potential connecting unit, wherein the control circuit controls the first and second reference potentials to generate the first and second current flows towards the first and second terminal simultaneously during a portion of a voltage monitoring period.