| 摘要 |
A first A/D converter converts an analog observed value, which corresponds to a power supply signal supplied to a power supply terminal of a DUT, into a digital observed value. By means of digital calculation processing, a digital signal processing circuit generates a control value that is adjusted such that the digital observed value matches a predetermined reference value. A first D/A converter supplies, via a power supply line to the power supply terminal of the DUT, an analog power supply signal obtained by performing digital/analog conversion of the control value. A load estimating unit applies a test signal containing a predetermined frequency component via the power supply line to a node via which the power supply terminal is to be connected, and generates a control parameter for the digital signal processing circuit according to the test signal and the observed signal. |
