Power supply system, a switched tank converter, and methods thereof

Patent metadata

Field	Value
Publication number	US-10778098-B2
Application number	US-201916369110-A
Country	US
Kind code	B2
Filing date	Mar 29, 2019
Priority date	Dec 22, 2018
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

A power supply system, which has a switched-tank converter with an adjustable conversion ratio, includes a first-stage power converter, a second-stage power converter, and a controller. The first-stage power converter converts a supply voltage to a first output voltage, and modulates the first output voltage according to a modulation signal. A second-stage power converter converts the first output voltage to a second output voltage, and generates a power signal according to the output power of the second output voltage. The controller determines, according to the power signal, whether the output power exceeds a threshold to generate the modulation signal.

First claim

What is claimed is:

1. A power supply system, comprising:
a first-stage power converter, converting a supply voltage into a first output voltage and modulating the first output voltage according to a modulation signal, wherein the first-stage power converter comprises:
an input capacitor, coupled between the supply voltage and a ground;
a first switch, providing the supply voltage to a first node according to a first control signal and the modulation signal;
a first resonant capacitor, coupled to the first node;
a first resonant inductor, coupled between the first resonant capacitor and a second node;
a second switch, coupling the second node to the first output voltage according to the first control signal and the modulation signal;
a third switch, coupling the second node to the ground according to a second control signal and the modulation signal;
a fourth switch, coupling the first node to a third node according to the first control signal, the second control signal, and the modulation signal;
a first fly capacitor, coupled between the third node and a fourth node;
a fifth switch, coupling the fourth node to the first output voltage according to the first control signal, the second control signal, and the modulation signal, wherein the fifth switch couples the fourth node to the first output voltage based on the state of the first control signal when the modulation signal is in a second logic level, and wherein the fifth switch couples the fourth node to the first output voltage based on the state of the second control signal when the modulation signal is in a first logic level; a sixth switch, coupling the fourth node to the ground according to the first control signal, the second control signal, and the modulation signal, wherein the sixth switch couples the fourth node to the ground based on the state of the second control signal when the modulation signal is in the second logic level, and wherein the sixth switch couples the fourth node to the ground based on the state of the first control signal when the modulation signal is in the first logic level; a seventh switch, coupling the third node to a fifth node according to the first control signal and the modulation signal; a second resonant capacitor, coupled to the fifth node; a second resonant inductor, coupled between the second resonant capacitor and a sixth node;
an eighth switch, coupling the sixth node to the first output voltage according to the first control signal;
a ninth switch, coupling the sixth node to the ground according to the second control signal;
a tenth switch, coupling the fifth node to a seventh node according to the second control signal, wherein the seventh node is coupled to the first output voltage; and
an output capacitor, coupled between the first output voltage and the ground, wherein the first control signal and the second control signal are out-of-phase;
a second-stage power converter, converting the first output voltage into a second output voltage and detecting output power of the second output voltage to generate a power signal; and
a controller, determining, according to the power signal, whether the output power exceeds a threshold to generate the modulation signal.

2. The power supply system of claim 1 , wherein the first-stage power converter increases, according to the modulation signal, the first output voltage in response to the output power exceeding the threshold.

3. The power supply system of claim 2 , wherein the first-stage power converter decreases, according to the modulation signal, the first output voltage in response to the output power not exceeding the threshold.

4. The power supply system of claim 3 , wherein the first-stage power converter is a switched tank converter having a conversion ratio, wherein the first-stage power converter decreases the conversion ratio to increase the first output voltage in response to the output power exceeding the threshold, wherein the first-stage power converter increases the conversion ratio to decrease the first output voltage in response to the output power not exceeding the threshold.

5. The power supply system of claim 3 , wherein the first-stage power converter is a power converter having a duty cycle, wherein in response to the output power exceeding the threshold, the first-stage power converter increases the duty cycle to increase the first output voltage, wherein in response to the output power not exceeding the threshold, the first-stage power converter decreases the duty cycle to decrease the first output voltage.

6. The power supply system of claim 1 , wherein the first-stage power converter further comprises:
a second fly capacitor, coupled to the seventh node and an eighth node;
an eleventh switch, coupling the eighth node to the first output voltage according to the second control signal;
a twelfth switch, coupling the eighth node to the ground according to the first control signal;
a thirteenth switch, coupling the seventh node to a ninth node according to the first control signal and the modulation signal;
a third resonant capacitor, coupled to the ninth node;
a third resonant inductor, coupled between the third resonant capacitor and a tenth node;
a fourteenth switch, coupling the tenth node to the first output voltage according to the first control signal, the second control signal, and the modulation signal;
a fifteenth switch, coupling the tenth node to the ground according to the first control signal, the second control signal, and the modulation signal;
a sixteenth switch, coupling the ninth node to an eleventh node according to the first control signal, the second control signal, and the modulation signal;
a third fly capacitor, coupled between the eleventh node and a twelfth node;
a seventeenth switch, coupling the twelfth node to the first output voltage according to the first control signal, the second control signal, and the modulation signal;
an eighteenth switch, coupling the twelfth node to the ground according to the first control signal, the second control signal, and the modulation signal;
a nineteenth switch, coupling the eleventh node to a thirteenth node according to the first control signal, and the modulation signal;
a fourth resonant capacitor, coupled to the thirteenth node;
a fourth resonant inductor, coupled between the fourth resonant capacitor and the fourteenth node;
a twentieth switch, coupling the fourteenth node to the first output voltage according to the first control signal;
a twenty-first switch, coupling the fourteenth node to the ground according to the second control signal; and
a twenty-second switch, coupling the thirteenth node to the first output voltage according to the second control signal.

7. The power supply system of claim 6 , wherein in response to the modulation signal in the first logic level, the first switch, the second switch, the sixth switch, the seventh switch, the eighth switch, the twelfth switch, the thirteenth switch, the fourteenth switch, the eighteenth switch, the nineteenth switch, and the twentieth switch are turned ON and OFF according to the first control signal, and the third switch, the fourth switch, the fifth switch, the ninth switch, the tenth switch, the eleventh switch, the fifteenth switch, the sixteenth switch, the seventeenth switch, the twenty-first switch, and the twenty-second switch are turned ON and OFF according to the second control signal, wherein the switched tank converter has a first conversion ratio, and the first output voltage is a ratio of the supply voltage to the first conversion ratio.

8. The power supply system of claim 7 , wherein in response to the modulation signal in the second logic level, the first switch, the third switch, the seventh switch, the thirteen

Assignees

• Wiwynn Corp

Inventors

• Yang Cheng Chung
• Huang Po-Chia

Classifications

• H02M7/4837

  Flying capacitor converters · CPC title

• H02M3/072

  adapted to generate an output voltage whose value is lower than the input voltage · CPC title

• H02M1/0048

  Circuits or arrangements for reducing losses (using snubbers H02M1/34) · CPC title

• H02M1/0058

  by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero (using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826) · CPC title

• H02M1/007

  Plural converter units in cascade (push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826) · CPC title