Patent ID: 6996489
Filing Date: 2006-02-07
Classification: G01R

Abstract:
1. A method for sampling a power supply current value for frequency analysis of the power supply current flowing in an integrated circuit when a test signal is applied to said integrated circuit, comprising steps of: (a) starting generation of a pre-established voltage and applying a power supply voltage to a power supply terminal of said integrated circuit; (b) starting generation of a test signal, and starting application of said test signal to an input/output terminal other than a power supply terminal of said integrated circuit; (c) generating a test signal application signal indicating application of said test signal along with the start of the application of said test signal; (d) observing a value of a power supply current supplied to said integrated circuit, and generating a power supply current value signal indicating said power supply current value; (e) starting sampling of said power supply current value signal simultaneously with the start of the application of said test signal to said integrated circuit; (f) ending sampling of said power supply current value signal when a pre-established amount of time has elapsed after the end of application of said test signal to said integrated circuit; and (g) performing a Fourier transformation on all data obtained by said sampling, and obtaining a frequency spectrum of said power supply current value signal.