# US 10,320,292 B2 · Phase compensation circuit and DC/DC converter using the same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,320,292 B2
- Document ID: US10320292B2
- Status: Granted
- Kind: B2
- Application number: 15/849,138
- Filed: 2017-12-20
- Published: 2018-06-28
- Granted: 2019-06-11
- Earliest claimed: 2016-12-27
- Assignees: Rohm Co., Ltd.
- Applicants: Rohm Co., Ltd.
- Inventors: Shun Fukushima; Shingo Hashiguchi; Tetsuo Tateishi
- Web page: https://patentgrep.com/patent/US10320292B2

## CPC

- H02M 3/156: with automatic control of output voltage or current, e.g. switching regulators
- G05F 1/575: characterised by the feedback circuit
- H02M 3/1588: {comprising at least one synchronous rectifier element (H02M3/1582, H02M3/1584 take precedence)}
- H03K 7/08: Duration or width modulation {; Duty cycle modulation}
- H02M 1/0032: {Control circuits allowing low power mode operation, e.g. in standby mode}
- Y02B 70/10: Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)
- G05F: SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
- H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M)
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

A phase compensation circuit, being for compensating phase of a first voltage inputted to a PWM comparator of a DC/DC converter having a sleep mode, includes: a phase compensation resistor part including a resistor; a phase compensation capacitor part including a plurality of capacitors; and a switch group arranged to change over the capacitors, in the sleep mode, to a first connection state in which at least one of the capacitors is charged with a first bias voltage and to change over the capacitors, at cancellation of the sleep mode, to a second connection state in which the first voltage is set to a desired initial value.

## Claims

### Claim 1

A phase compensation circuit for compensating phase of a first voltage inputted to a PWM comparator of a DC/DC converter having a sleep mode, the phase compensation circuit comprising:
a phase compensation resistor part including a resistor;
a phase compensation capacitor part including a plurality of capacitors; and
a switch group arranged to place the capacitors, in the sleep mode, into a first connection state in which at least one of the capacitors is charged with a first bias voltage and to place the capacitors, at cancellation of the sleep mode, into a second connection state in which the first voltage is set to a desired initial value, wherein
the switch group changes a connection destination of at least one of the plurality of capacitors in response to a sleep control signal,
the phase compensation capacitor part includes a first capacitor and a second capacitor each having a first terminal connected to a ground terminal, and
the switch group includes a first switch arranged to make connecting and/or disconnecting between a second terminal of the first capacitor and the ground terminal, and a second switch arranged to change whether a second terminal of the second capacitor is connected to an application terminal of the first bias voltage or to the second terminal of the first capacitor.

### Claim 2 (depends on 1)

The phase compensation circuit according to claim 1, wherein
given a capacitance value C1 of the first capacitor and a capacitance value C2 of the second capacitor, then it is satisfied that C2/C1=k/(1−k) (where 0<k<1), and amplitude of a second voltage to be compared with the first voltage by the PWM comparator is set to k times that of an input voltage or an output voltage of the DC/DC converter.

### Claim 3 (depends on 1)

The phase compensation circuit according to claim 1, wherein
the phase compensation capacitor part further includes a third capacitor having a first terminal connected to the ground terminal, and
the switch group further includes a third switch arranged to change whether a second terminal of the third capacitor is connected to an application terminal of a second bias voltage different from the first bias voltage or to the second terminal of the first capacitor.

### Claim 4 (depends on 3)

The phase compensation circuit according to claim 3, wherein
given a capacitance value C1 of the first capacitor, a capacitance value C2 of the second capacitor, and a capacitance value C3 of the third capacitor, then it is satisfied that C1:C2:C3={1−(k+k′)}:k:k′ (where 0<k<1 and 0<k′<1), and amplitude of a second voltage to be compared with the first voltage by the PWM comparator is set to k times that of an input voltage or an output voltage of the DC/DC converter.

### Claim 5 (depends on 1)

The phase compensation circuit according to claim 1, wherein
the resistor has a first terminal connected to an input terminal of the PWM comparator as well as a second terminal connected to the second terminal of the first capacitor.

### Claim 6 (depends on 5)

The phase compensation circuit according to claim 5, further comprising:
a switch arranged to make connecting and/or disconnecting between the input terminal of the PWM comparator and a stage circuit preceding the PWM comparator in response to the sleep control signal.

### Claim 7

A DC/DC converter comprising:
a switch output stage arranged to generate an output voltage from an input voltage;
an amplifier arranged to generate an error signal responsive to a differential between the output voltage or a feedback voltage responsive thereto and a specified reference voltage;
a phase compensation circuit arranged to generate a first voltage upon receiving input of the error signal;
an oscillator arranged to generate a second voltage of a ramp waveform;
a PWM comparator arranged to compare the first voltage and the second voltage to each other to generate a comparison signal; and
a driver arranged to generate a drive signal for the switch output stage in response to the comparison signal, wherein
the phase compensation circuit comprises:
a phase compensation resistor part including a resistor;
a phase compensation capacitor part including a plurality of capacitors; and
a switch group arranged to place the capacitors, in a sleep mode of the DC/DC converter, into a first connection state in which at least one of the capacitors is charged with a first bias voltage and to place the capacitors, at cancellation of the sleep mode, into a second connection state in which the first voltage is set to a desired initial value, wherein
the switch group changes a connection destination of at least one of the plurality of capacitors in response to a sleep control signal,
the phase compensation capacitor part includes a first capacitor and a second capacitor each having a first terminal connected to a ground terminal, and
the switch group includes a first switch arranged to make connecting and/or disconnecting between a second terminal of the first capacitor and the ground terminal, and a second switch arranged to change whether a second terminal of the second capacitor is connected to an application terminal of the first bias voltage or to the second terminal of the first capacitor.

### Claim 8 (depends on 7)

The DC/DC converter according to claim 7, wherein:
the switch output stage is a step-down type one, the first bias voltage is the output voltage, and amplitude of the second voltage is a variable value responsive to the input voltage; or
the switch output stage is a step-up type one, the first bias voltage is the input voltage, and amplitude of the second voltage is a variable value responsive to the output voltage.

### Claim 9

A phase compensation circuit for compensating phase of a first voltage inputted to a PWM comparator of a DC/DC converter adopting a current mode control method, the phase compensation circuit comprising:
a phase compensation resistor part and a phase compensation capacitor part, wherein
one of the phase compensation resistor part and the phase compensation capacitor part includes a plurality of resistors or a plurality of capacitors, and
an output voltage or an input voltage of the DC/DC converter is applied as a monitoring-target voltage to a grounding-side node of at least one of the plurality of resistors or the plurality of capacitors, wherein
the phase compensation capacitor part includes a first capacitor having a first terminal connected to a ground terminal as well as a second capacitor having a first terminal connected to an application terminal of the monitoring-target voltage, and the phase compensation resistor part includes a resistor having a first terminal connected to an input terminal of the PWM comparator as well as a second terminal connected to respective second terminals of the individual capacitors.

### Claim 10 (depends on 9)

The phase compensation circuit according to claim 9, wherein
given a capacitance value C1 of the first capacitor and a capacitance value C2 of the second capacitor, then it is satisfied that C2/C1=k/(1−k) (where 0<k<1), and amplitude of a second voltage to be compared with the first voltage by PWM comparator is set to k times that of the input voltage or the output voltage.

### Claim 11 (depends on 9)

The phase compensation circuit according to claim 9, further comprising switch means arranged to change a connection state of the individual capacitors in response to a sleep control signal, the switch means including:
a first switch arranged to make connection and/or disconnection between a second terminal of the first capacitor and the ground terminal, and a second switch arranged to change whether a first terminal of the second capacitor is connected to an application terminal of the monitoring-target voltage or to the ground terminal.

### Claim 12 (depends on 11)

The phase compensation circuit according to claim 11, further comprising
a switch arranged to make connection and/or disconnection between the input terminal of the PWM comparator and a stage circuit preceding the PWM comparator in response to the sleep control signal.

### Claim 13

A phase compensation circuit for compensating phase of a first voltage inputted to a PWM comparator of a DC/DC converter adopting a current mode control method, the phase compensation circuit comprising:
a phase compensation resistor part and a phase compensation capacitor part, wherein
one of the phase compensation resistor part and the phase compensation capacitor part includes a plurality of resistors or a plurality of capacitors, and
an output voltage or an input voltage of the DC/DC converter is applied as a monitoring-target voltage to a grounding-side node of at least one of the plurality of resistors or the plurality of capacitors, wherein
the phase compensation resistor part includes a first resistor having a first terminal connected to a ground terminal as well as a second resistor having a first terminal connected to an application terminal of the monitoring-target voltage, and the phase compensation capacitor part includes a capacitor having a first terminal connected to an input terminal of the PWM comparator as well as a second terminal connected to respective second terminals of the individual resistors.

### Claim 14 (depends on 13)

The phase compensation circuit according to claim 13, wherein
given a resistance value R1 of the first resistor and a resistance value R2 of the second resistor, then it is satisfied that R1/R2=k/(1−k) (where 0<k<1), and amplitude of a second voltage to be compared with the first voltage by the PWM comparator is set to k times that of the input voltage or the output voltage.

### Claim 15 (depends on 13)

The phase compensation circuit according to claim 13, further comprising switch means arranged to change over connection state of the individual resistors in response to a sleep control signal, the switch means including:
a first switch arranged to make connection and/or disconnection between a second terminal of the first resistor and the ground terminal;
a second switch arranged to make connection and/or disconnection between the first terminal of the second resistor and the application terminal of the monitoring-target voltage, and
a third switch arranged to make connection and/or disconnection between the first terminal of the capacitor and the ground terminal.

### Claim 16

A DC/DC converter comprising:
a switch output stage arranged to generate an output voltage from an input voltage;
a first amplifier arranged to generate a first error signal responsive to a differential between the output voltage or a feedback voltage responsive thereto and a specified reference voltage;
a first phase compensation circuit arranged to generate an error voltage upon receiving input of the first error signal;
a clamper arranged to restrict the error voltage to under a specified upper-limit voltage value;
a current detector arranged to generate a current sense voltage responsive to a coil current of the switch output stage;
a second amplifier arranged to generate a second error signal responsive to a differential between the error voltage and the current sense voltage;
a second phase compensation circuit arranged to output a first voltage upon receiving input of the second error signal;
an oscillator arranged to generate a second voltage of a ramp waveform;
a PWM comparator arranged to compare the first voltage and the second voltage to each other to generate a comparison signal; and
a driver arranged to generate a drive signal for the switch output stage in response to the comparison signal, wherein
the second phase compensation circuit comprises a phase compensation resistor part and a phase compensation capacitor part, wherein
one of the phase compensation resistor part and the phase compensation capacitor part includes a plurality of resistors or a plurality of capacitors, and
the output voltage or the input voltage of the DC/DC converter is applied as a monitoring-target voltage to a grounding-side node of at least one of the plurality of resistors or the plurality of capacitors, wherein
the phase compensation capacitor part includes a first capacitor having a first terminal connected to a ground terminal as well as a second capacitor having a first terminal connected to an application terminal of the monitoring-target voltage, and the phase compensation resistor part includes a resistor having a first terminal connected to an input terminal of the PWM comparator as well as a second terminal connected to respective second terminals of the individual capacitors.

### Claim 17 (depends on 16)

The DC/DC converter according to claim 16, wherein:
the switch output stage is a step-down type one, the monitoring-target voltage is the output voltage, and amplitude of the second voltage is a variable value responsive to the input voltage; or
the switch output stage is a step-up type one, the monitoring-target voltage is the input voltage, and amplitude of the second voltage is a variable value responsive to the output voltage.

### Claim 18

A DC/DC converter comprising:
a switch output stage arranged to generate an output voltage from an input voltage;
an amplifier arranged to generate an error signal responsive to a differential between the output voltage or a feedback voltage responsive thereto and a specified reference voltage;
a phase compensation circuit arranged to generate an error voltage upon receiving input of the error signal;
a clamper arranged to restrict the error voltage to under a specified upper-limit voltage value;
a current detector arranged to generate a current sense voltage responsive to a coil current of the switch output stage;
a computing unit arranged to generate a first voltage by computing process of the error voltage and the current sense voltage;
an oscillator arranged to generate a second voltage of a ramp waveform;
a PWM comparator arranged to compare the first voltage and the second voltage to each other to generate a comparison signal; and
a driver arranged to generate a drive signal for the switch output stage in response to the comparison signal, wherein
the phase compensation circuit comprises a phase compensation resistor part and a phase compensation capacitor part, wherein
one of the phase compensation resistor part and the phase compensation capacitor part includes a plurality of resistors or a plurality of capacitors, and
the output voltage or the input voltage of the DC/DC converter is applied as a monitoring-target voltage to a grounding-side node of at least one of the plurality of resistors or the plurality of capacitors, wherein
the phase compensation capacitor part includes a first capacitor having a first terminal connected to a ground terminal as well as a second capacitor having a first terminal connected to an application terminal of the monitoring-target voltage, and the phase compensation resistor part includes a resistor having a first terminal connected to an input terminal of the PWM comparator as well as a second terminal connected to respective second terminals of the individual capacitors.

### Claim 19

A DC/DC converter comprising:
a switch output stage arranged to generate an output voltage from an input voltage;
an amplifier arranged to generate an error signal responsive to a differential between the output voltage or a feedback voltage responsive thereto and a specified reference voltage;
a phase compensation circuit arranged to generate a first voltage upon receiving input of the error signal;
a clamper arranged to restrict the first voltage to under a specified upper-limit voltage value;
a current detector arranged to generate a current sense voltage responsive to a coil current of the switch output stage;
an oscillator arranged to generate a second voltage of a ramp waveform;
a computing unit arranged to generate a third voltage by computing process of the second voltage and the current sense voltage;
a PWM comparator arranged to compare the first voltage and the third voltage to each other to generate a comparison signal; and
a driver arranged to generate a drive signal for the switch output stage in response to the comparison signal, wherein
the phase compensation circuit comprises a phase compensation resistor part and a phase compensation capacitor part, wherein
one of the phase compensation resistor part and the phase compensation capacitor part includes a plurality of resistors or a plurality of capacitors, and
the output voltage or the input voltage of the DC/DC converter is applied as a monitoring-target voltage to a grounding-side node of at least one of the plurality of resistors or the plurality of capacitors, wherein
the phase compensation capacitor part includes a first capacitor having a first terminal connected to a ground terminal as well as a second capacitor having a first terminal connected to an application terminal of the monitoring-target voltage, and the phase compensation resistor part includes a resistor having a first terminal connected to an input terminal of the PWM comparator as well as a second terminal connected to respective second terminals of the individual capacitors.

### Claim 20

A DC/DC converter comprising:
a switch output stage arranged to generate an output voltage from an input voltage;
a first amplifier arranged to generate a first error signal responsive to a differential between the output voltage or a feedback voltage responsive thereto and a specified reference voltage;
a first phase compensation circuit arranged to generate an error voltage upon receiving input of the first error signal;
a clamper arranged to restrict the error voltage to under a specified upper-limit voltage value;
a current detector arranged to generate a current sense voltage responsive to a coil current of the switch output stage;
a second amplifier arranged to generate a second error signal responsive to a differential between the error voltage and the current sense voltage;
a second phase compensation circuit arranged to output a first voltage upon receiving input of the second error signal;
an oscillator arranged to generate a second voltage of a ramp waveform;
a PWM comparator arranged to compare the first voltage and the second voltage to each other to generate a comparison signal; and
a driver arranged to generate a drive signal for the switch output stage in response to the comparison signal, wherein
the second phase compensation circuit comprises a phase compensation resistor part and a phase compensation capacitor part, wherein
one of the phase compensation resistor part and the phase compensation capacitor part includes a plurality of resistors or a plurality of capacitors, and
the output voltage or the input voltage of the DC/DC converter is applied as a monitoring-target voltage to a grounding-side node of at least one of the plurality of resistors or the plurality of capacitors, wherein
the phase compensation resistor part includes a first resistor having a first terminal connected to a ground terminal as well as a second resistor having a first terminal connected to an application terminal of the monitoring-target voltage, and the phase compensation capacitor part includes a capacitor having a first terminal connected to an input terminal of the PWM comparator as well as a second terminal connected to respective second terminals of the individual resistors.

### Claim 21 (depends on 20)

The DC/DC converter according to claim 20, wherein:
the switch output stage is a step-down type one, the monitoring-target voltage is the output voltage, and amplitude of the second voltage is a variable value responsive to the input voltage; or
the switch output stage is a step-up type one, the monitoring-target voltage is the input voltage, and amplitude of the second voltage is a variable value responsive to the output voltage.

### Claim 22

A DC/DC converter comprising:
a switch output stage arranged to generate an output voltage from an input voltage;
an amplifier arranged to generate an error signal responsive to a differential between the output voltage or a feedback voltage responsive thereto and a specified reference voltage;
a phase compensation circuit arranged to generate an error voltage upon receiving input of the error signal;
a clamper arranged to restrict the error voltage to under a specified upper-limit voltage value;
a current detector arranged to generate a current sense voltage responsive to a coil current of the switch output stage;
a computing unit arranged to generate a first voltage by computing process of the error voltage and the current sense voltage;
an oscillator arranged to generate a second voltage of a ramp waveform;
a PWM comparator arranged to compare the first voltage and the second voltage to each other to generate a comparison signal; and
a driver arranged to generate a drive signal for the switch output stage in response to the comparison signal, wherein
the phase compensation circuit comprises a phase compensation resistor part and a phase compensation capacitor part, wherein
one of the phase compensation resistor part and the phase compensation capacitor part includes a plurality of resistors or a plurality of capacitors, and
the output voltage or the input voltage of the DC/DC converter is applied as a monitoring-target voltage to a grounding-side node of at least one of the plurality of resistors or the plurality of capacitors, wherein
the phase compensation resistor part includes a first resistor having a first terminal connected to a ground terminal as well as a second resistor having a first terminal connected to an application terminal of the monitoring-target voltage, and the phase compensation capacitor part includes a capacitor having a first terminal connected to an input terminal of the PWM comparator as well as a second terminal connected to respective second terminals of the individual resistors.

### Claim 23

A DC/DC converter comprising:
a switch output stage arranged to generate an output voltage from an input voltage;
an amplifier arranged to generate an error signal responsive to a differential between the output voltage or a feedback voltage responsive thereto and a specified reference voltage;
a phase compensation circuit arranged to generate a first voltage upon receiving input of the error signal;
a clamper arranged to restrict the first voltage to under a specified upper-limit voltage value;
a current detector arranged to generate a current sense voltage responsive to a coil current of the switch output stage;
an oscillator arranged to generate a second voltage of a ramp waveform;
a computing unit arranged to generate a third voltage by computing process of the second voltage and the current sense voltage;
a PWM comparator arranged to compare the first voltage and the third voltage to each other to generate a comparison signal; and
a driver arranged to generate a drive signal for the switch output stage in response to the comparison signal, wherein
the phase compensation circuit comprises a phase compensation resistor part and a phase compensation capacitor part, wherein
one of the phase compensation resistor part and the phase compensation capacitor part includes a plurality of resistors or a plurality of capacitors, and
the output voltage or the input voltage of the DC/DC converter is applied as a monitoring-target voltage to a grounding-side node of at least one of the plurality of resistors or the plurality of capacitors, wherein
the phase compensation resistor part includes a first resistor having a first terminal connected to a ground terminal as well as a second resistor having a first terminal connected to an application terminal of the monitoring-target voltage, and the phase compensation capacitor part includes a capacitor having a first terminal connected to an input terminal of the PWM comparator as well as a second terminal connected to respective second terminals of the individual resistors.