Patent ID: 6498519
Filing Date: 2002-12-24
Classification: G01R

Abstract:
A voltage control circuit for detecting which one of an external voltage supplied from the outside and a reference voltage serving as a standard for comparison is higher, the circuit comprising:an input terminal to which the external voltage is applicable via a voltage dropping resistor; voltage converting means for converting, in conjunction with the voltage dropping resistor, the external voltage applied to the input terminal to a voltage lower than the external voltage; and comparing means for comparing a converted voltage outputted from the voltage converting means with a specified comparison voltage corresponding to the reference voltage and outputting a signal indicative of the result of comparison as a signal indicative of which one of the external voltage and the reference voltage is higher, said converted voltage and said reference voltage being generated by separate sources, the voltage converting means performing a voltage conversion such that a ratio of an increment of the converted voltage to an increment of the external voltage is non-linear over a given range of the external voltage.