Phase compensation circuit and DC/DC converter using the same

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.

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.

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.

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.

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.

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.

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.

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.

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.