Methods of operating step-up DC voltage converters and step-up DC voltage converters

摘要

The invention relates to methods of operating step-up DC voltage converters including a storage choke, the one terminal of which is connected to the input of the converter and the other terminal of which is connectable via a first controllable switch to ground and via a second controllable switch to the output of the converter; a clock outputting a first clock signal dictating the switching cycle of the converter, and a second clock signal, the cycle of which corresponds to that of the first clock signal; and a regulator circuit which regulates the voltage at the output of the converter to a setpoint value. In the methods the second switch is set ON at the end of the switching cycle during a constant time duration as dictated by the second clock signal and which as compared to the length of the switching cycles is short, whilst the first switch is set OFF, so that a transient flow of energy occurs from the output of the converter to the input of the converter. Due to this, the converter is always operable at a constant frequency independent of the load and thus permits simple noise filtering of the output voltage which is particularly of advantage in telecommunication applications. The invention relates furthermore to step-up DC voltage converters for implementing the method.