Controller for DC-DC converter and method for controlling DC-DC converter

A DC-DC converter for generating output voltage from input voltage, the DC-DC converter comprising:

• a first output transistor;
• a second output transistor electrically connected in series to the first output transistor;
• a choke coil electrically connected to a node between the first output transistor and the second output transistor with at least either one of the first output transistor and the second output transistor being operated to generate the output voltage of the DC-DC converter based on the input voltage;
• a smoothing capacitor, electrically connected to the choke coil, for smoothing the output voltage of the DC-DC converter;
• and
• a controller, electrically connected to the first output transistor and the second output transistor, for controlling the first output transistor and the second output transistor in a first operation mode, a second operation mode, or a third operation mode based on the output voltage of the DC-DC converter or output current, in which the output current changes in accordance with the output voltage, wherein the controller activates and inactivates the first output transistor and the second output transistor in a complementary manner during the first operation mode, the controller inactivates the second output transistor and activates and inactivates the first output transistor during the second operation mode, and the controller inactivates the second output transistor and performs linear operation with the first output transistor during the third operation mode,
• wherein the controller includes an error amplifier which generates a first error signal based on a differential voltage between the output voltage and a first reference voltage and a second error signal that is complementary to the first error signal, and
• wherein the controller activates and inactivates the first output transistor and the second output transistor in a complementary manner by a control signal in accordance with the first error signal during the first operation mode, the controller inactivates the second output transistor and activates and inactivates the first output transistor by the control signal during the second operation mode, and the controller inactivates the second output transistor and performs linear operation with the first output transistor by the second error signal during the third operation mode.

A controller for a DC-DC converter including a first output transistor, a second output transistor electrically connected in series to the first output transistor, a choke coil electrically connected to a node between the first output transistor and the second output transistor with at least either one of the first output transistor and the second output transistor being operated to generate output voltage of the DC-DC converter based on input voltage, and a smoothing capacitor, electrically connected to the choke coil, for smoothing the output voltage of the DC-DC converter, wherein the controller comprising:

• a circuit for controlling the first output transistor and the second output transistor in a first operation mode or a second operation mode based on the output voltage of the DC-DC converter or output current, in which the output current changes in accordance with the output voltage,
• wherein the circuit includes an error amplifier which generates a first error signal based on a differential voltage between the output voltage and a first reference voltage and a second error signal that is complementary to the first error signal, the circuit activating and inactivating the first output transistor and the second output transistor in a complementary manner by a control signal in accordance with the first error signal during the first operation mode, and inactivating the second output transistor and performing linear operation with the first output transistor by the second error signal during the second operation mode.

A controller for a DC-DC converter including a first output transistor, a second output transistor electrically connected in series to the first output transistor, a choke coil electrically connected to a node between the first output transistor and the second output transistor with at least either one of the first output transistor and the second output transistor being operated to generate output voltage of the DC-DC converter based on input voltage, a smoothing capacitor, electrically connected to the choke coil, for smoothing the output voltage of the DC-DC converter, wherein the controller comprising:

• a circuit for controlling the first output transistor and the second output transistor in a first operation mode, a second operation mode, or a third operation mode based on the output voltage of the DC-DC converter or output current, in which the output current changes in accordance with the output voltage,
• wherein the circuit includes an error amplifier which generates a first error signal based on a differential voltage between the output voltage and a first reference voltage and a second error signal that is complementary to the first error signal, the circuit activating and inactivating the first output transistor and the second output transistor in a complementary manner by a control signal in accordance with the first error signal during the first operation mode, inactivating the second output transistor and activating and inactivating the first output transistor by the control signal during the second operation mode, and inactivating the second output transistor and performing linear operation with the first output transistor by the second error signal during the third operation mode.

A method for controlling a DC-DC converter for generating output voltage from input voltage, the DC-DC converter including a first output transistor, a second output transistor electrically connected in series to the first output transistor, a choke coil electrically connected to a node between the first output transistor and the second output transistor with at least either one of the first output transistor and the second output transistor being operated to generate the output voltage of the DC-DC converter based on the input voltage, and a smoothing capacitor, electrically connected to the choke coil, for smoothing the output voltage of the DC-DC converter, the method comprising:

• detecting the output voltage of the DC-DC converter or output current, in which the output current changes in accordance with the output voltage;
• controlling the first output transistor and the second output transistor in a first operation mode or a second operation mode based on the detected output voltage or the output current;
• said controlling including:
• activating and inactivating the first output transistor and the second output transistor in a complementary manner by a control signal in accordance with a first error signal during the first operation mode, wherein the first error signal is generated based on a differential voltage between the output voltage and a first reference voltage;
• and
• inactivating the second output transistor and performing linear operation with the first output transistor by a second error signal during the second operation mode, wherein the second error signal is generated complementary to the first error signal.

A method for controlling a DC-DC converter for generating output voltage from input voltage, the DC-DC converter including a first output transistor, a second output transistor electrically connected in series to the first output transistor, a choke coil electrically connected to a node between the first output transistor and the second output transistor with at least either one of the first output transistor and the second output transistor being operated to generate the output voltage of the DC-DC converter based on the input voltage, a smoothing capacitor, electrically connected to the choke coil, for smoothing the output voltage of the DC-DC converter, the method comprising:

• detecting the output voltage of the DC-DC converter or output current, in which the output current changes in accordance with the output voltage;
• controlling the first output transistor and the second output transistor in a first operation mode, a second operation mode, or a third operation mode based on the detected output voltage or the output current;
• said controlling including:
• activating and inactivating the first output transistor and the second output transistor in a complementary manner by a control signal in accordance with a first error signal during the first operation mode, wherein the first error signal is generated based on a differential voltage between the output voltage and a first reference voltage;
• inactivating the second output transistor and activating and inactivating the first output transistor by the control signal during the second operation mode;
• and
• inactivating the second output transistor and performing linear operation with the first output transistor by a second error signal during the third operation mode, wherein second error signal is generated complementary to the first error signal.