A demodulator has a resistor and a capacitor that may be subject to tolerances.
For tolerance correction, the FM demodulator is preferably supplied with a reference
frequency, which corresponds to the nominal mid-frequency of the demodulator, which
is a function of the resistor and the capacitor. Any discrepancy between the actual
mid-frequency of the demodulator and its nominal mid-frequency leads to the production
of a voltage that differs from a nominal voltage at the output. A detector detects
this error and adjusts the values of the resistor or capacitor until the error
between the nominal voltage and the voltage is zero or is a minimum. The described
principle can be used, for example, in integrated mobile radio receivers.