Trimming method and trimming device for a PLL circuit for two-point modulation

摘要

In the case of a trimming method for a PLL circuit operating based on the principle of a two-point modulation, the PLL circuit is locked without any modulation being impressed and then an analog and a digital modulation signal are impressed into the locked PLL circuit. A signal that is characteristic of the PLL control error is tapped from the PLL circuit, and the modulation swing in the analog modulation signal is changed such that the characteristic signal has the same value as before the analog and digital modulation signals were impressed.