Patent ID: 6518900
Filing Date: 2003-02-11
Classification: H03M

Abstract:
A method for testing an A/D converter, said method including the use of a ramp signal generator for generating a ramp voltage that is delivered to the input of the A/D converter, and a test circuit for activating a test cycle which comprises a first run of the ramp signal generator, by which a reference measurement of the ramp signal generator is carried out for compensating component tolerances, and comprises a second run of the ramp signal generator where an error signal is output when the value that is calculated for a transmission characteristic of the A/D converter lies outside a predetermined tolerance range of the measured value of the transmission characteristic, said method including the steps of:passing the ramp signal generator through first and second ramp runs, wherein the first run of the ramp includes measuring the period of time that is necessary for a ramp run, wherein this time is used to determine the number of sampling operations needed to reach the maximum ramp voltage wherein the transmission characteristic is the output voltage calculated for one or a plurality of sampling operations, and the error signal is produced when the said output voltage lies outside a predetermined tolerance range of the output voltage measured with these sampling operations.