US 12,487,621 B2
Low dropout regulator
Yi Feng, Hsinchu (TW); and Hsueh-Yu Kao, Hsinchu (TW)
Assigned to Realtek Semiconductor Corporation, Hsinchu (TW)
Filed by Realtek Semiconductor Corporation, Hsinchu (TW)
Filed on Mar. 9, 2023, as Appl. No. 18/180,868.
Claims priority of application No. 111139493 (TW), filed on Oct. 18, 2022.
Prior Publication US 2024/0126314 A1, Apr. 18, 2024
Int. Cl. G05F 1/575 (2006.01); G05F 3/26 (2006.01)
CPC G05F 1/575 (2013.01) [G05F 3/26 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A low dropout regulator, comprising:
an output terminal circuit configured to generate an output voltage according to an input voltage and configured to generate a feedback voltage according to the output voltage; and
an amplifier configured to generate a control voltage to the output terminal circuit according to a reference voltage and the feedback voltage, so as to adjust the output voltage, wherein the amplifier comprises:
an input stage circuit configured to receive the reference voltage and the feedback voltage to generate a differential output;
a current mirror circuit coupled to the input stage circuit; and
a filter circuit coupled to the current mirror circuit and configured to filter the input voltage to generate a dependent current related to a noise of the input voltage on the current mirror circuit, wherein the current mirror circuit is configured to output the control voltage according to the differential output and the dependent current.