Device and method for measuring jitter

A test device contains a data pattern generator for providing a delta-sigma-modulated data stream sampled with a sampling frequency fs at its output. A phase modulator generates a test clock subjected to jitter and having the clock frequency ft at its output. The output of the data pattern generator is connected to a terminal for connection to a data input of a semiconductor component to be tested. The output of the phase modulator is connected to a terminal for connection to a clock input of a semiconductor component to be tested. An evaluation device determines the jitter parameters of the input signal at the input of the data device from the low-frequency component of the input signal. In this case, the low-frequency component contains only frequency components of frequencies which are less than half the sampling frequency fs/2.