Method for trimming a two-point modulator, and a two-point modulator having a trimming apparatus

摘要

A PLL circuit (1) is regulated by means of a digital modulation signal (28) at a first frequency, and is then regulated at a second frequency, by deactivation of the digital modulation signal (28). A difference signal (32), which is characteristic of the voltage change in a control signal (22) for the VCO (7) which is produced by deactivation of the digital modulation signal (28) is compared with an analog modulation signal (34). The analog modulation signal (34) is changed so as to correct any discrepancy determined during the comparison.