Abstract: An electrical test circuit is disclosed. In one embodiment, the electrical test circuit includes a first input for receiving a test signal of an integrated circuit, a second input for receiving a control signal and a third input for receiving a normalized reference signal, particularly one that is formed to be synchronous with the test signal. Using a control device of the electrical test circuit, the deviation and/or the amplitude and/or the phase of the reference signal and/or of the test signal can be varied. A measuring device generates, by subtracting the reference signal from the test signal, a difference signal which is output via an output.

Abstract: A method for testing AD converters (10) may have the steps of a) producing a digital test signal, b) producing an analog test signal as input signal for the AD converter (10) from the digital test signal, c) producing a sinusoidal, digital reference signal whose frequency is equal to or an integer multiple of the frequency of the analog test signal, d) mixing the test response from the AD converter (10) with the sine and the cosine of the digital reference signal to form mixed signals, e) determining the DC components of the mixed signals, and f) determining at least one of the parameters including amplitude, power components and phase angle for a fundamental or harmonic of the test response from the DC components of the mixed signals.

Abstract: A method for testing AD converters (10) may have the steps of a) producing a digital test signal, b) producing an analog test signal as input signal for the AD converter (10) from the digital test signal, c) producing a sinusoidal, digital reference signal whose frequency is equal to or an integer multiple of the frequency of the analog test signal, d) mixing the test response from the AD converter (10) with the sine and the cosine of the digital reference signal to form mixed signals, e) determining the DC components of the mixed signals, and f) determining at least one of the parameters including amplitude, power components and phase angle for a fundamental or harmonic of the test response from the DC components of the mixed signals.

Abstract: The electrical test circuit (5) comprises a first input (51) for receiving a test signal of an integrated circuit (4), a second input (52) for receiving a control signal and a third input (53) for receiving a normalized reference signal, particularly one that is formed to be synchronous with the test signal. Using a control device (55) of the electrical test circuit (5), the deviation and/or the amplitude and/or the phase of the reference signal and/or of the test signal can be varied. A measuring device (56) generates, by subtracting the reference signal from the test signal, a difference signal which is output via an output (54).