Patent ID: 6317340
Filing Date: 2001-11-13
Classification: H02M

Abstract:
A circuit configuration for driving a pulse width modulator in a switched mode power supply, comprising:a difference formation stage having a first input terminal for receiving a control signal, a second input terminal for receiving a reference signal, and an output terminal for providing a drive signal;said difference formation stage forming a difference signal from the control signal and the reference signal, and amplifying the difference signal by a gain factor dependent on at least one of the drive signal and the control signal for providing an amplified difference signal;said difference formation stage including a multiplier and a feedback path;said multiplier including a multiplier output connected to said output terminal, a first multiplier input terminal for receiving the amplified difference signal, and a second multiplier input terminal;said feedback path having an output connected to said second multiplier input terminal and including an amplifier having a gain range extending between a top limit and at a bottom limit; andsaid amplifier producing, based on the drive signal fed back into said feedback path via said multiplier output, a first constant output signal if the drive signal has a value below a first limit value, and said amplifier producing a second constant output signal if the drive signal has a value above a second limit value.