Dual-mode low dropout regulator with fast transient switching between modes
The present disclosure relates to a dual mode, low dropout regulator circuit and method of using the same. The circuit may include a multiplexer configured to switch between a high-speed mode and a low-power mode and an error amplifier configured to generate an amplifier output. The circuit may include a class AB circuit configured to receive the amplifier output and generate a class AB output and a unity feedback circuit in electrical communication with the class AB circuit, wherein a single reference voltage is applied to perform a dual mode operation.
1. A dual mode, low dropout regulator circuit comprising:
a multiplexer configured to switch between a high-speed mode and a low-power mode;
an error amplifier configured to generate an amplifier output;
a class AB circuit configured to receive the amplifier output and generate a class AB output;
a unity feedback circuit in electrical communication with the class AB circuit, wherein a single reference voltage is applied to perform a dual mode operation, wherein the unity feedback circuit and the class AB circuit electrically communicate with the multiplexer to switch between the high-speed mode and the low-power mode.
2. The dual mode, low dropout regulator circuit of claim 1 , wherein the low dropout regulator generates a first power supply in the low-power mode.
3. The dual mode, low dropout regulator circuit of claim 2 , wherein the low dropout regulator generates a second power supply in a high speed mode.
4. The dual mode, low dropout regulator circuit of claim 1 , wherein the low dropout regulator is included in a display PHY (D-PHY) architecture.
5. The dual mode, low dropout regulator circuit of claim 3 , wherein the second power supply is provided to a pre-driver circuit.
6. The dual mode, low dropout regulator circuit of claim 5 , wherein the pre-driver circuit is a thin oxide device.
7. The dual mode, low dropout regulator circuit of claim 1 , wherein the unity feedback circuit includes at least one capacitor operatively connected to a plurality of resistors arranged in parallel.
8. The dual mode, low dropout regulator circuit of claim 1 , further comprising:
a controller configured to provide a toggle signal to the multiplexer.
9. The dual mode, low dropout regulator circuit of claim 3 , wherein the first power supply is approximately 1.2 volts and the second power supply is approximately 0.9 volts.
10. A method of low dropout regulator mode switching, comprising:
applying a single reference voltage at a unity feedback circuit in electrical communication with a class AB circuit to enable a dual mode operation;
switching, using a multiplexer, between a high-speed mode and a low-power mode;
generating an amplifier output using an error amplifier; and
receiving the amplifier output at the class AB circuit and generating a class AB output, wherein the unity feedback circuit and the class AB circuit electrically communicate with the multiplexer to switch between the high-speed mode and the low-power mode.
11. The method of claim 10 , wherein the low dropout regulator generates a first power supply in the low-power mode.
12. The method of claim 11 , wherein the low dropout regulator generates a second power supply in the high-speed mode.
13. The method of claim 10 , wherein the low dropout regulator is included in a display PHY (D-PHY) architecture.
14. The method of claim 12 , wherein the second power supply is provided to a pre-driver circuit.
15. The method of claim 14 , wherein the pre-driver circuit is a thin oxide device.
16. The method of claim 10 , wherein the unity feedback circuit includes at least one capacitor operatively connected to a plurality of resistors arranged in parallel.
17. The method of claim 10 , further comprising:
a controller configured to provide a toggle signal to the multiplexer.
18. The method of claim 12 , wherein the first power supply is approximately 1.2 volts and the second power supply is approximately 0.9 volts.