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US 6,333,623 B1Granted
Complementary follower output stage circuitry and method for low dropout voltage regulator
AssigneeTexas Instruments Incorporated
InventorsDavid A. Heisley, Tony R. Larson
Life of this patent
Estimating the term…
Abstract
A low drop-out (“LDO”) voltage regulator includes an output stage of having a pass device and a discharge device arranged in complementary voltage follower configurations to both source load current to and sink load current from a regulated output voltage conductor. The pass device and the discharge device are controlled through a single feedback loop.
Claims24
A voltage regulator comprising:
- an error amplifier having a first input coupled to a first reference voltage, a second input, and an output configured to produce a first control signal;
- a pass transistor having a drain coupled to an unregulated input voltage conductor, a source coupled to a regulated output voltage conductor, and a gate configured to receive the first control signal;
- a discharge transistor having a source coupled to the regulated output voltage conductor, a drain coupled to a second reference voltage, and a gate configured to receive a second control signal;
- and
- a feedback circuit coupled between the regulated output voltage conductor and the second input of the error amplifier.
2 more elements
A voltage regulator comprising:
- a first pass device coupled between an unregulated input voltage conductor and a regulated output voltage conductor, the first pass device configured to respond to a first control signal;
- and
- a second pass device coupled between the regulated output voltage conductor and a reference voltage, the second pass device configured to respond to a second control signal;
- wherein the first and second pass devices are coupled in a complementary voltage follower configuration.
1 more element
A method of regulating voltage, the method comprising:
- providing an input voltage to be regulated on an input conductor;
- generating an output voltage on an output conductor;
- generating a first control signal in response to a voltage difference between a sample of the output voltage and a reference voltage;
- passing current from the input conductor to the output conductor in response to the first control signal;
- passing current from the output conductor to ground in response to a second control voltage;
- and
- simultaneously passing charge from the input conductor to the output conductor and passing charge from the output conductor to ground for a portion of a transition between providing charge to the output conductor and removing charge from the output conductor.
4 more elements
A voltage regulator comprising:
- an error amplifier having a first input coupled to a first reference voltage, a second input, and an output configured to produce a first control signal;
- a pass transistor having a drain coupled to an unregulated input voltage conductor, a source coupled to a regulated output voltage conductor, and a gate configured to receive the first control signal;
- a discharge transistor having a source coupled to the regulated output voltage conductor, a drain coupled to a second reference voltage, and a gate configured to receive a second control signal;
- and
- a single feedback circuit coupled between the regulated output voltage conductor and the second input of the error amplifier and operative to provide a single control loop from the regulated output voltage conductor to provide the same control signal variation to the gates of the pass transistor and the discharge transistor.
2 more elements
Dependencies are inferred from the claim text.