SELF-OSCILLATING SWITCHING REGULATOR WITH SECONDARY SWITCHING CONTROL SIGNAL TO REGULATE SWITCHING FREQUENCY

摘要

A self-oscillating switching regulator is frequency regulated by the introduction of secondary switching control signals into the voltage regulation feedback loop to delay switching of the switching device. The secondary switching control signal is generated by a monostable circuit with a frequency responsive time constant. The secondary switching control signal comprises a variable duration pulse signal. This pulse signal is tacked onto the trailing edge of the conventional switching control signal and hence extends the duration of the control signal applied to the switching device. The switching delay introduced by the secondary control signal directly regulates the switching frequency of the switching regulator.