US 11,989,045 B2
LDO with self-calibrating compensation of resonance effects
Satish Kumar Vangara, Woodley (GB); and Amr Ahmed Kamel, Reading (GB)
Assigned to pSemi Corporation, San Diego, CA (US)
Filed by pSemi Corporation, San Diego, CA (US)
Filed on Oct. 28, 2021, as Appl. No. 17/513,112.
Claims priority of application No. 20205374 (EP), filed on Nov. 3, 2020.
Prior Publication US 2022/0137656 A1, May 5, 2022
Int. Cl. G05F 1/575 (2006.01); G05F 1/565 (2006.01)
CPC G05F 1/575 (2013.01) [G05F 1/565 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A low drop-out (LDO) regulator circuit configured to be coupled to a capacitive load, the LDO regulator circuit including:
(a) a pass field-effect transistor (FET) including a control gate and configured to produce a voltage output from an input voltage;
(b) a driver FET including a control gate and configured to provide a control voltage to the control gate of the pass FET;
(c) a feedback loop coupled between the voltage output and an internal node;
(d) a low pass filter (LPF) coupled between the internal node and the control gate of the driver FET and settable to one of a plurality of tuning states in response to application of an N-bit binary signal to the LPF; and
(e) an oscillation detector and filter bit control circuit, coupled to a voltage output of the LDO regulator circuit and to the LPF, and configured to detect an oscillation in the voltage output of the LDO regulator circuit and to generate a filter bit pattern as the N-bit binary signal as a function of the detected oscillation, wherein the N-bit binary signal selects one of the plurality of tuning states of the LPF to at least partially control the oscillation in the voltage output of the LDO regulator circuit.