Power output circuit having a pulse-width modulation mode and a permanently closed mode
AssigneeRobert Bosch GmbH
InventorsHarald Eisenhardt, Rolf Falliano
Life of this patent
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Abstract
A power output circuit having a pulse-width modulation generator and an upstream closed-loop control circuit which switches the pulse-width modulation generator and the power output stage to a permanently open mode, a PWM mode having pulse-width-modulated pulses, and a permanently closed mode as a function of a preset external setpoint, an actual value of the power output stage, and a reference voltage derived from the supply voltage. High power loss and high EMC in the full-load threshold region are avoided by prematurely switching from the PWM mode to the permanently closed mode as a function of a preset setpoint and the supply voltage, and returning to the PMW mode with a hysteresis of these values.
Claims7
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.
Dependencies are inferred from the claim text.