Switched capacitor power supply circuit

Patent metadata

Field	Value
Publication number	US-9973080-B2
Application number	US-201615060749-A
Country	US
Kind code	B2
Filing date	Mar 4, 2016
Priority date	Sep 2, 2015
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

According to one embodiment, a switched capacitor power supply circuit includes a switched capacitor power supply circuit unit that supplies a voltage obtained by converting an input voltage with a predetermined conversion ratio as an output voltage by switching a connection configuration between a plurality of capacitors that perform charge and discharge, and a control circuit that switches the connection configuration between the plurality of capacitors according to the output voltage to change the conversion ratio.

First claim

What is claimed is:

1. A switched capacitor power supply circuit comprising a switched capacitor power supply circuit unit, the switched capacitor power supply circuit unit comprising:
an input terminal to which an input voltage is applied;
an output terminal that outputs an output voltage;
a first connection node;
a second connection node;
a third connection node;
a fourth connection node;
a fifth connection node;
a sixth connection node;
a first capacitor connected between the third and fourth connection nodes;
a second capacitor connected between the fifth and sixth connection nodes;
a third capacitor connected between the first and second connection nodes;
a first switching element connected between the fourth connection node and ground;
a second switching element connected between the output terminal and the sixth connection node;
a third switching element connected between the sixth connection node and the ground;
a fourth switching element connected between the output terminal and the third connection node;
a fifth switching element connected between the output terminal and the fifth connection node;
a sixth switching element connected between the output terminal and the fourth connection node;
a seventh switching element connected between the first and fifth connection nodes;
an eighth switching element connected between the input terminal and the first connection node;
a ninth switching element connected between the input terminal and the second connection node;
a tenth switching element connected between the second and third connection nodes; and
a control circuit configured to switch between on and off states of each of the first to tenth switching elements to obtain a predetermined conversion ratio, wherein
while the switched capacitor power supply circuit unit is keeping the predetermined conversion ratio for a certain period, the control circuit is further configured to:
select a first group of one or more of the first to tenth switching elements based on the predetermined conversion ratio;
keep the selected first group of one or more switching elements in on or off state for the certain period;
select a second group of one or more of unselected switching elements of the first to tenth switching elements based on the predetermined conversion ratio;
identify the eighth switching element as a switching element to be turned on and off in a first phase which has a predetermined cycle during the certain period;
alternately turn on and off the selected second group of one or more switching elements and the eighth switching element in the first phase during the certain period;
identify the seventh switching element as a switching element to be turned on and off in a second phase which is complementary to the first phase; and
alternately turn on and off unselected and unidentified switching elements among the first to tenth switching elements and the seventh switching element in the second phase during the certain period.

2. The switched capacitor power supply circuit according to claim 1 , wherein the switched capacitor power supply circuit unit further includes an eleventh switching element connected between the third and fifth connection nodes.

3. The switched capacitor power supply circuit according to claim 2 , wherein the switched capacitor power supply circuit unit further includes:
a twelfth switching element connected between the input terminal and the sixth connection node; and
a thirteenth switching element connected between the input terminal and the fourth connection node.

4. A switched capacitor power supply circuit comprising:
a switched capacitor power supply circuit unit including a plurality of capacitors and configured to change a connection configuration between the plurality of capacitors to supply to an output terminal a voltage obtained by converting an input voltage with a predetermined conversion ratio as an output voltage; and
a control circuit configured to supply to the switched capacitor power supply circuit unit a control signal for changing the conversion ratio by changing the connection configuration between the plurality of capacitors according to the output voltage,
wherein
the switched capacitor power supply circuit unit includes:
an input terminal to which the input voltage is applied;
an output terminal that outputs the output voltage;
a first connection node;
a second connection node;
a third connection node;
a fourth connection node;
a fifth connection node;
a sixth connection node;
a first capacitor connected between the third and fourth connection nodes;
a second capacitor connected between the fifth and sixth connection nodes;
a third capacitor connected between the first and second connection nodes;
a first switching element connected between the fourth connection node and ground;
a second switching element connected between the output terminal and the sixth connection node;
a third switching element connected between the sixth connection node and the ground;
a fourth switching element connected between the output terminal and the third connection node;
a fifth switching element connected between the output terminal and the fifth connection node;
a sixth switching element connected between the output terminal and the fourth connection node;
a seventh switching element connected between the first and fifth connection nodes;
an eighth switching element connected between the input terminal and the first connection node;
a ninth switching element connected between the input terminal and the second connection node; and
a tenth switching element connected between the second and third connection nodes, wherein
the control circuit is configured to switch between on and off states of each of the first to tenth switching elements to obtain a predetermined conversion ratio, wherein
while the switched capacitor power supply circuit unit is keeping the predetermined conversion ratio for a certain period, the control circuit is further configured to:
select a first group of one or more of the first to tenth switching elements based on the predetermined conversion ratio;
keep the selected first group of one or more switching elements in on or off state for the certain period;
select a second group of one or more of unselected switching elements of the first to tenth switching elements based on the predetermined conversion ratio;
identify the eighth switching element as a switching element to be turned on and off in a first phase which has a predetermined cycle during the certain period;
alternately turn on and off the selected second group of one or more switching elements and the eighth switching element in the first phase during the certain period;
identify the seventh switching element as a switching element to be turned on and off in a second phase which is complementary to the first phase; and
alternately turn on and off unselected and unidentified switching elements among the first to tenth switching elements and the seventh switching element in the second phase during the certain period.

5. The switched capacitor power supply circuit according to claim 4 , wherein the control circuit changes, among a plurality of switching elements connected between the plurality of capacitors, a combination of switching elements that are turned on while the predetermined conversion ratio keeps unchanged, according to the input voltage so as to change the conversion ratio.

6. The switched capacitor power supply circuit according to claim 5 , wherein the control circuit operates in synchronization with a predetermined clock signal.

7. The switched capacitor power supply circuit according to claim 5 , further comprising a conversion ratio selection circuit

Assignees

• Toshiba Kk

Inventors

• Teh Chen Kong

Classifications

• H02M3/07 Primary

  using capacitors charged and discharged alternately by semiconductor devices with control electrode {, e.g. charge pumps} · CPC title