摘要:
A d.c. signal controlled oscillator includes a frequency-determining network having a control input and a modulation input. A phase regulating loop includes the oscillator and components that provide a control signal to the control input. A circuit apparatus for driving the oscillator includes a modulation generator that provides a modulation signal to the modulation input, and a circuit arrangement that autonomously generates a signal depending on and representing a slope of the modulation and provides this slope signal to the modulation generator, which generates the modulation signal dependent on the slope signal. A method of operating the oscillator involves switching a frequency divider successively to two different frequencies, respectively sampling and holding the two different arising control voltages, forming a difference between the two control voltages, and activating the modulation generator so that a modulation swing of the modulation signal is determined by this difference between the control voltages.