Patent ID: 9459642
Filing Date: 2016-10-04
CPC Classification: G05F

Claim Text:
1. A device comprising: an error amplifier having a negative input terminal and a positive input terminal; a standby current source having a control terminal electrically connected to an output terminal of the error amplifier, wherein the standby current source has a first transistor and a standby ratio equal to a first channel width of the first transistor divided by a first channel length of the first transistor; a voltage divider having: an input terminal electrically connected to an output terminal of the standby current source, and an output terminal electrically connected to the positive input terminal of the error amplifier; a charging current source having a control terminal electrically connected to the output terminal of the error amplifier, wherein the charging current source has a second transistor and a charging ratio equal to a second channel width of the second transistor divided by a second channel length of the second transistor, wherein the charging ratio is at least twice as large as the standby ratio; a first switch having: a first terminal electrically connected to an input terminal of the charging current source, and a second terminal electrically connected to a first power supply node; and a compensation circuit having: a first capacitor, wherein a first terminal of the first capacitor is electrically coupled to the output terminal of the error amplifier; a first resistor, wherein a first terminal of the first resistor is electrically coupled to a second terminal of the first capacitor, and a second terminal of the first resistor is electrically coupled to the input terminal of the voltage divider; a second resistor, wherein a first terminal of the second resistor is electrically coupled to the second terminal of the first capacitor; and a second switch, wherein a first terminal of the second switch is electrically coupled to a second terminal of the second resistor, and a second terminal of the second switch is electrically coupled to the input terminal of the voltage divider; wherein the second switch is configured to close when the charging current source provides a driving current to the output terminal of the standby current source, and wherein the second switch and the charging current source are configured to be controlled by a same control signal.