DC-DC converter with adaptive phase compensation controller
A DC-DC converter for generating an output voltage from input voltage, includes: an output stage for outputting the output voltage; an error amplifier having an input and a reference input for receiving a feedback voltage at the input in accordance with the output voltage and for receiving a reference voltage at the reference input, the error amplifier generating an amplified voltage for driving the output stage, the amplifier voltage corresponding to the difference between the feedback voltage and the reference voltage; a phase compensation unit for generating a phase compensation component to the feedback voltage; and a phase compensation controller for controlling the phase of the phase compensation unit; wherein the feedback voltage is determined by the output voltage plus said phase compensation component.
1. A DC-DC converter for generating an output voltage from an input voltage, comprising:
an output stage to output the output voltage generated based on the input voltage;
an error amplifier having an input for receiving a feedback voltage in accordance with the output voltage, a first input for receiving a reference voltage and an output for generating an amplified voltage which drives the output stage, the amplified voltage corresponding to the difference between the feedback voltage and the reference voltage;
a phase compensation circuit to adjust a phase of the feedback voltage; and
a phase compensation controller to control a phase compensation component of the phase compensation circuit based on the input voltage and the output voltage,
wherein the phase compensation circuit includes a variable capacitor having a transistor whose backgate is coupled to a second input of the error amplifier,
wherein a capacitance of the variable capacitor is controlled based on a control voltage so as to become small when the control voltage becomes large and to become large when the control voltage becomes small,
wherein the control voltage is generated by amplifying a voltage difference between the input voltage and the output voltage.
2. The DC-DC converter of claim 1 , wherein the phase compensation circuit is a serial circuit including the variable capacitor and a resistor electrically connected between the input and the output, and wherein the phase compensation controller controls capacitance of the variable capacitor.
3. The DC-DC converter of claim 1 , wherein the phase compensation circuit is a serial circuit including the variable capacitor and a resistor electrically connected between the input and the output, and wherein the phase compensation controller controls capacitance of the variable capacitor.
4. The DC-DC converter of claim 2 , wherein the transistor is an N-channel floating MOS transistor including a gate of the N-channel MOS transistor receiving a control signal from the phase compensation controller.
5. The DC-DC converter of claim 3 , wherein the transistor is an N-channel floating MOS transistor including a gate of the N-channel MOS transistor receiving a control signal from the phase compensation controller.
6. The DC-DC converter of claim 1 , wherein the phase compensation circuit is a serial circuit including the variable capacitor and a variable resistor electrically connected between the input and the output, and wherein the phase compensation controller controls resistance of the variable resistor.
7. The DC-DC converter of claim 1 , wherein the phase compensation circuit is a serial circuit including the variable capacitor and a variable resistor electrically connected between the input and the output, and wherein the phase compensation controller controls resistance of the variable resistor.
8. The DC-DC converter of claim 6 , wherein the variable resistor is an N-channel MOS transistor, a gate of the N-channel MOS transistor receiving a control signal from the phase compensation controller, a drain of the N-channel MOS transistor electrically connecting to the output, a source of the N-channel MOS transistor electrically connecting to the input.
9. The DC-DC converter of claim 7 , wherein the variable resistor is an N-channel MOS transistor, a gate of the N-channel MOS transistor receiving a control signal from the phase compensation controller, a drain of the N-channel MOS transistor electrically connecting to the output, a source of the N-channel MOS transistor electrically connecting to the input.
10. The DC-DC converter of claim 1 , wherein the phase compensation circuit is a serial circuit including the variable capacitor and a variable resistor electrically connected between the input and the output, and wherein the phase compensation controller controls capacitance of the variable capacitor.
11. The DC-DC converter of claim 1 , wherein the phase compensation circuit is a serial circuit including the variable capacitor and a variable resistor electrically connected between the input and the output, and wherein the phase compensation controller controls and capacitance of the variable capacitor.
12. The DC-DC converter of claim 10 , wherein the variable capacitor is an N-channel MOS transistor, the gate of the N-channel MOS transistor receiving a control signal from the phase compensation controller, and wherein the variable resistor is an N-channel MOS transistor, the gate of the N-channel MOS transistor receiving the control signal from the phase compensation controller.
13. The DC-DC converter of claim 10 , wherein the variable capacitor is an N-channel MOS transistor, the gate of the N-channel MOS transistor receiving a control signal from the phase compensation controller, and wherein the variable resistor is an N-channel MOS transistor, the gate of the N-channel MOS transistor receiving the control signal from the phase compensation controller.
14. The DC-DC converter of claim 4 , wherein the phase compensation controller generates a difference voltage between the feedback voltage and the input voltage and wherein the phase compensation controller outputs the control signal in accordance with the difference voltage to the gate of the each N-channel MOS transistor.
15. The DC-DC converter of claim 5 , wherein the phase compensation controller generates a difference voltage between the feedback voltage and the input voltage and wherein the phase compensation controller outputs the control signal in accordance with the difference voltage to the gate of the each N-channel MOS transistor.
16. The DC-DC converter of claim 8 , wherein the phase compensation controller generates a difference voltage between the feedback voltage and the input voltage and wherein the phase compensation controller outputs the control signal in accordance with the difference voltage to the gate of the each N-channel MOS transistor.
17. The DC-DC converter of claim 9 , wherein the phase compensation controller generates a difference voltage between the feedback voltage and the input voltage and wherein the phase compensation controller outputs the control signal in accordance with the difference voltage to the gate of the each N-channel MOS transistor.
18. The DC-DC converter of claim 12 , wherein the phase compensation controller generates a difference voltage between the feedback voltage and the input voltage and wherein the phase compensation controller outputs the control signal in accordance with the difference voltage to the gate of the each N-channel MOS transistor.
19. The DC-DC converter of claim 13 , wherein the phase compensation controller generates a difference voltage between the feedback voltage and the input voltage and wherein the phase compensation controller outputs the control signal in accordance with the difference voltage to the gate of the each N-channel MOS transistor.
20. The DC-DC converter of claim 13 , wherein the phase compensation circuit includes a resistor coupled to a source and a drain of the transistor.