Method for regulating a voltage and circuit therefor

A method for regulating a voltage, comprising:

• comparing a feedback voltage to first and second reference voltages;
• generating at least one control signal in response to comparing the feedback voltage to the first reference voltage;
• generating a second control signal in response to comparing the feedback voltage to the second reference voltage;
• passing the second control signal to a circuit in response to the at least one control signal;
• and
• passing a third control signal to the circuit in response to at least one other control signal that is the complement of the at least one control signal.

A voltage regulator, comprising:

• an undershoot limitation circuit, comprising:
• a transconductance amplifier having first and second inputs and an output, the first input coupled for receiving a feedback voltage and the second input coupled for receiving a first reference voltage;
• a comparator having first and second inputs and an output, the first input coupled for receiving the feedback voltage and the second input coupled for receiving a second reference voltage, the first reference voltage greater than the second reference voltage;
• and
• an switching circuit having first and second inputs and an output, the first input coupled to the output of the transconductance amplifier and the second input coupled to the output of the comparator;
• and
• a regulation circuit having an input and an output, the input coupled to the output of the undershoot limitation circuit.

A method for regulating a voltage, comprising:

• providing first and second reference signals;
• comparing a feedback signal with the first reference signal;
• generating a first control signal in response to the comparison between the feedback signal and the first reference signal;
• generating a second control signal in response to the feedback signal being different from the second reference signal;
• and
• using the first and second control signals to control the operating state of an undershoot limitation circuit.

A voltage regulator, comprising:

• an undervoltage protection circuit comprising:
• a comparator having first and second inputs and an output, the first input coupled for receiving a feedback voltage and the second input coupled for receiving a first reference voltage;
• a transconductance amplifier having first and second inputs and an output, the first input coupled for receiving the feedback voltage and the second input coupled for receiving a second reference voltage, the first reference voltage less than the second reference voltage;
• and
• a switching circuit having first, second, and third inputs and an output, the first input coupled to the output of the transconductance amplifier and the second input coupled to the output of the comparator;
• a regulation circuit having an input and an output, the input coupled to the output of the undervoltage protection circuit;
• and
• a start detection circuit having an input and an output, the input coupled for receiving a control signal and the output coupled to the third input of the undershoot protection circuit.

A voltage regulator, comprising:

• a first comparator having first and second inputs and an output, the first input coupled for receiving a feedback voltage and the second input coupled for receiving a first reference voltage;
• a second comparator having first and second inputs and an output, the first input coupled for receiving the feedback voltage and the second input coupled for receiving a second reference voltage, the first reference voltage less than the second reference voltage;
• a voltage protection circuit having first, second, and third inputs and an output, the first input coupled to the output of the first comparator and the second input coupled to the output of the second comparator;
• a regulation circuit having an input and an output, the input coupled to the output of the voltage protection circuit;
• a buffer circuit having an input and an output, the input coupled to the output of the first comparator;
• a first switch having first and second conductors, the first conductor coupled to the output of the second comparator and the output of the buffer circuit operatively coupled to the first switch;
• and
• a second switch having first and second conductors, the first conductor coupled to the second conductor of the first switch and the output of the first comparator operatively coupled to the second switch.

A method for regulating a voltage, comprising:

• providing first and second reference signals;
• comparing a feedback signal with the first reference signal;
• generating a first control signal in response to the comparison between the feedback signal and the first reference signal;
• generating a second control signal in response to the feedback signal being different from the second reference signal;
• and
• using the first control signal to control the operating state of an undershoot limitation circuit by operatively coupling the first control signal to a first switch and operatively coupling a complementary first control signal to a second switch.