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US 12,756,308 B2Granted
PFM transition hysteresis scheme for peak-current mode buck converters
AssigneesNexperia Technology (Shanghai) Ltd., Nexperia B.V.
InventorsAlejandro Vera, Jairo Olivares, Amer Atrash
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Abstract
A peak-current mode (PCM), buck converter is provided, including a slope compensation element, the PCM buck converter is arranged to detect an entering or exiting of a pulse frequency modulation (PFM), mode of operation. The slope compensation element is arranged to disable or reduce a slope compensation when the PCM buck converter detects the entering of the PFM. The slope compensation element is arranged to enable the slope compensation when the PCM buck converter detects the exiting of the PFM.
Claims12
A peak-current mode (PCM) buck converter comprising:
- a slope compensation element;
- and
- an inductor;
- wherein the PCM buck converter is arranged to detect entering or exiting of a pulse frequency modulation (PFM) mode of operation and introduce PFM transition hysteresis into a convertor loop of the buck converter by a sudden change in a peak of an inductor current by enabling and disabling slope compensation,
- wherein the slope compensation element is arranged to disable or greatly reduce a slope compensation when the PCM buck converter detects the entering of the PFM,
- wherein the PCM buck converter is arranged to increase the peak in an Inductor current through the inductor by disabling or greatly reducing the slope compensation when detecting the entering of the PFM,
- wherein the slope compensation element is arranged to enable the slope compensation when the PCM buck converter detects the exiting of the PFM, and
- wherein the PCM buck converter is arranged to decrease the peak in the inductor current through the inductor by enabling the slope compensation when detecting the exiting of the PEM.
5 more elements
A slope compensation element of a peak-current mode (PCM) buck converter,
- wherein the slope compensation element is arranged to disable or greatly reduce a slope compensation when the PCM buck converter detects an entering of a pulse frequency modulation (PFM) mode of operation, wherein the slope compensation element is arranged to enable the slope compensation when the PCM buck converter detects an exiting of the PFM mode of operation,
- wherein enabling and disabling the slope compensation introduces PFM transition hysteresis into a convertor loop of the buck converter by a sudden change in a peak of an inductor current of the buck converter, and
- wherein the slope compensation element is arranged to be triggered by a PFM activation signal (PFM_ACT) from a PFM comparator to enable or disable the slope compensation.
A clamp circuit of a peak-current mode (PCM) buck converter,
- wherein the clamp circuit is arranged to receive an error amplifier (EA) output voltage (VCOMP) from an EA,
- wherein the clamp circuit comprises a pulse frequency modulation (PFM) comparator arranged to receive a PFM detection voltage (PFM_DET), and wherein the PFM_DET is based on the VCOMP,
- wherein the PFM comparator is arranged to generate a PFM activation signal (PFM_ACT) by comparing the PFM_DET with a reference voltage for PFM detection (VREF_PFM_DET),
- wherein the PFM comparator is arranged to output PFM_ACT to a slope compensation element for triggering the slope compensation element to enable or disable a slope compensation when the PCM buck converter enters or exits a pulse frequency modulation (PFM) mode of operation so that the PCM buck converter introduces PFM transition hysteresis into a convertor loop of the buck converter by a sudden change in a peak of an inductor current by enabling and disabling the slope compensation, and
- wherein the clamp circuit comprises a clamp amplifier arranged to receive the VCOMP from the EA and arranged to regulate the VCOMP to a reference voltage for PFM (VREF_PFM), and wherein the clamp circuit comprises one or more transistors arranged to gain up the VREF_PFM to obtain the PEM_DET.
2 more elements
A clamp circuit of a peak-current mode (PCM) buck converter,
- wherein the clamp circuit is arranged to receive an error amplifier (EA) output voltage (VCOMP) from an EA,
- wherein the clamp circuit comprises a pulse frequency modulation (PFM) comparator arranged to receive a PFM detection voltage (PEM_DET), and wherein the PFM_DET is based on the VCOMP,
- wherein the PFM comparator is arranged to generate a PFM activation signal (PEM_ACT) by comparing the PEM_DET with a reference voltage for PEM detection (VREF_PFM_DET),
- wherein the PFM comparator is arranged to output PFM_ACT to a slope compensation element for triggering the slope compensation element to enable or disable a slope compensation when the PCM buck converter enters or exits a pulse frequency modulation (PFM) mode of operation so that the PCM buck converter introduces PEM transition hysteresis into a convertor loop of the buck converter by a sudden change in a peak of an inductor current by enabling and disabling the slope compensation, and wherein the clamp circuit is further arranged to generate a signal to a converter oscillator for PFM frequency foldback.
1 more element
Dependencies are inferred from the claim text.