Low dropout regulator circuit with reduced overshoot and undershoot and the method thereof
AssigneeChengdu Monolithic Power Systems Co., Ltd.
InventorYong Zhou
Life of this patent
Estimating the term…
Abstract
A low dropout regulator circuit with reduced overshoot and undershoot during transient state is discussed. The low dropout regulator circuit has a power device operating at a restive region, a first amplification stage and a second amplification stage. The first amplification stage amplifies a difference between a feedback voltage and a reference voltage to generate a positive signal and a negative signal. The feedback voltage is derived from an output voltage via a feedback resistor network. The second amplification stage amplifies a difference between the positive signal and a sum of a feed forward signal and the negative signal to generate an amplified signal. The feed forward signal is derived from an output voltage via a capacitor network.
Claims16
A low dropout regulator circuit, comprising:
- a power device, configured to operate at a resistive region, to convert an input voltage to an output voltage;
- a first amplification stage, configured to receive a feedback voltage indicative of the output voltage by way of a feedback resistor network, to generate a positive signal and a negative signal by amplifying a difference between the feedback voltage and a reference voltage;
- and
- a second amplification stage, configured to receive a feed forward signal indicative of the output voltage by way of a feedback capacitor, to generate an amplified signal by amplifying a difference between the positive signal and a sum of the feed forward signal and the negative signal, to control the power device;
- wherein
- the first amplification stage is powered by a first power supply, and the second amplification stage is powered by a second power supply;
- and wherein
- the second power supply has a voltage value higher than the first power supply.
A low dropout regulator circuit, comprising:
- a power device, configured to operate at a resistive region, to convert an input voltage to an output voltage;
- a first amplification stage, configured to receive a feedback voltage indicative of the output voltage by way of a feedback resistor network, to generate a positive signal and a negative signal by amplifying a difference between the feedback voltage and a reference voltage;
- and
- a second amplification stage, configured to receive a feed forward signal indicative of the output voltage by way of a feedback capacitor, to generate an amplified signal by amplifying a difference between the negative signal and an algebraic difference of the feed forward signal and the positive signal, to control the power device;
- wherein:
- the first amplification stage is powered by a first power supply, and the second amplification stage is powered by a second power supply;
- and wherein
- the second power supply has a voltage value higher than the first power supply.
A method used in a LDO regulator circuit, comprising:
- controlling a power device to operate at a resistive region, to convert an input voltage to an output voltage;
- receiving a feedback voltage indicative of the output voltage by way of a feedback resistor network, and amplifying a difference between the feedback voltage and a reference voltage to generate a positive signal and a negative signal;
- and
- receiving a feed forward signal indicative of the output voltage by way of a feedback capacitor, and amplifying a difference between the positive signal and a sum of the feed forward signal and the negative signal to generate an amplified signal, to control the power device;
- wherein:
- the first amplification stage is powered by a first power supply, and the second amplification stage is powered by a second power supply;
- and wherein
- the second power supply has a voltage value higher than the first power supply.
Dependencies are inferred from the claim text.