Switching mode power supply with an anti-windup circuit including a voltage clamping circuit
The anti-windup circuit generally has a voltage clamping device in series with a current limiting device operatively connectable to the output current path of a feedback compensator; the feedback compensator being part of a switch-mode power supply (SMPS) having an input voltage source and a load and generating constrained control values required to generate control on-off actions for tight power regulation. The inclusion of the disclosed anti-windup circuit in an SMPS may lead to hardware based overvoltage protection, reduced overall size and faster response to load changes.
1. A switching mode power supply comprising:
a converter;
a voltage input for the converter;
a voltage output from the converter and configured to electrically couple to a load;
a feedback compensator controlling the converter in response to detecting the voltage output; and
an anti-windup circuit comprising a current limiting circuit connected in a series combination with a voltage clamping circuit;
wherein the series combination of the current limiting circuit and the voltage clamping circuit of the anti-windup circuit is connected in parallel with an output current path of the feedback compensator.
2. The switching mode power supply of claim 1 , wherein the feedback compensator generates a control signal for controlling the converter.
3. The switching mode power supply of claim 2 , wherein the feedback compensator generates the control signal using a comparison between the detected voltage output and a reference voltage to reduce a deviation of the voltage output.
4. The switching mode power supply of claim 3 , wherein the control signal of the feedback compensator decreases towards a negative value control signal when the voltage output exceeds the reference voltage, wherein the anti-windup circuit prevents occurrences or minimizes an absolute value of negative value control signals from the feedback compensator.
5. The switching mode power supply of claim 4 , wherein the feedback compensator comprises a proportional-integral-derivative controller.
6. The switching mode power supply of claim 2 , wherein the control signal controls a pulse width modulator, the pulse width modulator providing switching input to the converter.
7. The switching mode power supply of claim 2 , wherein the feedback compensator generates the control signal according to at least one of discontinuous-current modulation (DCM), continuous-current modulation (CCM), pulse-frequency modulation (PFM), or quasi-resonant frequency (QR) operation.
8. The switching mode power supply of claim 1 , wherein the voltage clamping circuit comprises at least one of a Zener diode, a shunt regulator, an active Zener device, a transient voltage suppression (TVS) diode, a voltage-dependent resistor (VDR), or an avalanche diode.
9. The switching mode power supply of claim 1 , wherein the current limiting circuit comprises at least one of a field-effect transistor, a resistor, a thermistor, or an active current limiter.
10. The switching mode power supply of claim 1 , wherein the feedback compensator comprises an analog feedback compensator.
11. The switching mode power supply of claim 10 , wherein the feedback compensator isolates the voltage output from a control signal of the converter.
12. The switching mode power supply according to claim 11 , wherein the feedback compensator is isolated using an opto-coupler.
13. The switching mode power supply of claim 1 , wherein the voltage input is configured to receive either an alternating current or a direct current.
14. The switching mode power supply according to claim 1 , wherein the converter comprises a flyback converter.
15. The switching mode power supply of claim 1 , wherein the anti-windup circuit minimizes deviation of the voltage output during light-to-heavy transients.
16. The switching mode power supply of claim 1 , wherein the voltage clamping circuit provides transient overvoltage protection.
17. A method of converting voltage input into a voltage output, the method comprises:
receiving the voltage input at a converter;
converting the voltage input into the voltage output using the converter;
connecting the voltage output to a load;
detecting the voltage output across the load;
controlling the converter in response to the detected voltage output using a feedback compensator; and
reducing a voltage output deviation using an anti-windup circuit comprising a voltage clamping circuit connected in a series combination with a current limiting circuit, the series combination of the current limiting circuit and the voltage clamping circuit being connected in parallel with an output current path of the feedback compensator.