Liquid detection device and liquid detection method

Abstract

A liquid detection device includes a pull-down circuit, a pull-up circuit, and a comparison circuit. The pull-down circuit is coupled to at least one signal pin of a universal serial bus. The pull-down circuit resets a signal voltage of the at least one signal pin during a reset period. The pull-up circuit is coupled to the at least one signal pin. The pull-up circuit charges the at least one signal pin for a predetermined time during a charging period. After the predetermined time ends, the comparison circuit compares whether the signal voltage is larger than at least one reference voltage during a detection period. If the signal voltage is larger than the at least one reference voltage, the comparison circuit generates an output signal so as to determine that the at least one signal pin is in contact with liquid according to the output signal.

Images