US 12,719,366 B2Granted

Switch control circuit and method, power conversion system

AssigneeHalo Microelectronics Co., Ltd.

InventorsYang Xu, Wenchao Qu

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Abstract

A switch control circuit comprises a comparison branch and a feedback branch. The comparison branch controls the turning off of the second power switch in the power conversion circuit based on the polarity of the voltage difference between the common node and the first voltage. The feedback branch generates a feedback signal based on the polarity of the first signal after the second power switch is turned off and a delay of the first duration and adjusts the first voltage. The first signal can be a voltage difference or the voltage of the common node. If the polarity of the first signal is positive, the first voltage is reduced to make the comparison branch turn off the second power switch earlier. If the polarity of the first signal is negative, the first voltage is increased to make the comparison branch delay the turning off of the second power switch.

Claims19

Dependent claims

A switch control circuit applied to a power conversion circuit, wherein the power conversion circuit comprises a first power switch, a second power switch, and an inductor, and wherein the first power switch and the second power switch are connected between an input voltage bus and ground, and the inductor is connected between a common node of the first power switch and the second power switch and an output voltage bus, and wherein the switch control circuit comprises a comparison branch and a feedback branch, and wherein the comparison branch is connected to the feedback branch, and wherein:

the comparison branch is used to receive a voltage on the common node of the first power switch and the second power switch, and based on a polarity of a voltage difference between the voltage on the common node and a first voltage, output a control signal for turning off the second power switch;
and
the feedback branch is used to output a feedback signal based on a polarity of a first signal after the comparison branch turns off the second power switch and delays by a first time duration, and to adjust the first voltage based on the feedback signal, and wherein the first signal is the voltage difference or the voltage on the common node, and wherein if the polarity of the first signal is positive, the first voltage is decreased to turn off the second power switch prematurely, and if the polarity of the first signal is negative, the first voltage is increased to delay the turning off of the second power switch.

A switch control method, applicable to a power conversion circuit, wherein the power conversion circuit comprises a first power switch, a second power switch, and an inductor, and wherein the first power switch and the second power switch are connected between an input voltage bus and ground, and the inductor is connected between a common node of the first power switch and the second power switch, and an output voltage bus, and wherein the switch control method comprises the following steps:

controlling the second power switch to turn off based on a polarity of a voltage difference between a voltage on the common node and a first voltage;
and
introducing a delay of a first duration every time when the second power switch is controlled to turn off, and, after the first duration has elapsed, adjusting the first voltage based on a polarity of a first signal, and wherein the first signal is either the voltage difference or the voltage on the common node, and wherein if the voltage polarity is positive, the first voltage is reduced to control the second power switch to turn off earlier, and if the voltage polarity is negative, the first voltage is increased to control the second power switch to turn off later.

A power conversion system comprising:

a first power switch and a second power switch connected between an input voltage bus and ground;
an inductor connected between a common node of the first power switch and the second power switch, and an output voltage bus;
an output capacitor connected between the output voltage bus and ground;
and
a switch control circuit comprising a comparison branch and a feedback branch connected to the comparison branch, wherein:
the comparison branch is configured to receive a voltage on the common node of the first power switch and the second power switch, and based on a polarity of a voltage difference between the voltage on the common node and a first voltage, the comparison branch is configured to generate a control signal for turning off the second power switch;
and
the feedback branch is configured to generate a feedback signal based on a polarity of a first signal after the comparison branch turns off the second power switch and delays by a first time duration, and the feedback branch is configured to adjust the first voltage based on the feedback signal, and wherein:
the first signal is the voltage difference between the voltage on the common node and the first voltage or the voltage on the common node, and wherein:
if the polarity of the first signal is positive, the first voltage is decreased to turn off the second power switch prematurely;
and
if the polarity of the first signal is negative, the first voltage is increased to delay the turning off of the second power switch.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/527,199Filed 1 Dec 2023
Published: US 2025/0105737 A127 Mar 2025
Granted: 25 Aug 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

H02M 3/158
With automatic control of output voltage or current, e.g. switching regulators: including plural semiconductor devices as final control devices…
H02M 1/0025
Details of control, feedback or regulation circuits: arrangements for modifying reference values, feedback values or error values in the control…
H02M 1/0058
Transistor switching losses: by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current…
H02M 3/157
With automatic control of output voltage or current, e.g. switching regulators: with digital control