Patent ID: 6445168
Filing Date: 2002-09-03
Classification: H02M

Abstract:
A circuit arrangement, comprising:a power output stage generating an output signal having a signal value; a pulse-width modulation generator; a closed-loop control circuit positioned upstream from the pulse-width modulation generator and for switching the pulse-width modulation generator and, via the pulse-width modulation generator, the power output stage to a permanently open state, a pulse-width modulation (PWM) mode and a permanently closed state, wherein the closed-loop control circuit is configured to switch the pulse-width modulation generator and switch, via the pulse-width modulation generator, the power output stage as a function of a predetermined external setpoint, the signal value of the power output stage and a reference voltage derived from a supply voltage, wherein the closed-loop control circuit is configured to prematurely switch, via the pulse-width modulation generator, the power output stage from the PWM mode to the permanently closed state as a function of the predetermined external setpoint and the supply voltage, and switch, via the pulse-width modulation generator, the power output stage back to the PWM mode with a hysteresis of values, wherein the closed-loop control circuit receives a bias voltage, and wherein the closed-loop control circuit is configured to prematurely and abruptly switch the pulse-width modulation generator and switch, via the pulse-width modulation generator, the power output stage to the permanently closed state as a function of the bias voltage and the predetermined external setpoint, the predetermined external setpoint being smaller than a maximum setpoint which generates a maximum pulse width.