Patent ID: 6339388
Filing Date: 2002-01-15
Classification: G01R

Abstract:
A test method for a mixed analog/digital integrated circuit including a digital circuit, an A/D converter for converting an analog input signal from an external input terminal to a converted digital signal to said digital circuit and a D/A converter for converting a digital output signal from said digital circuit to a converted analog signal to an external output terminal, said digital circuit operates according to said converted digital signal, said test method comprising the steps of:disconnecting said D/A converter from said digital circuit; disconnecting said A/D converter from said external input terminal and said digital circuit; converting a series of sample digital signals to a first analog signal by said D/A converter; converting said first analog signal to a series of first digital signals by said A/D converter; comparing whether or not said series of said first digital signals coincides with said series of said sample digital signals; attenuating said first analog signal by a predetermined attenuation factor to obtain a second analog signal; converting said second analog signal to a series of second digital signals by said A/D converter; multiplying said series of second digital signals by a multiplying factor equal to the reciprocal of said predetermined attenuation factor to obtain a series of third digital signals; and comparing whether or not said series of said third digital signals coincides with said series of said sample digital signals.