Voltage overshoot dampener in dropout condition

A voltage regulator circuit, comprising:

• a reference generation circuit having a reference input and a reference output, the reference input coupled to an input voltage terminal;
• a first amplifier having first and second amplifier inputs and a first amplifier output, the first amplifier input coupled to the reference output, and the second amplifier input coupled to an output voltage terminal;
• a second amplifier having a third amplifier input and a second amplifier output, the third amplifier input coupled to the first amplifier output;
• a first transistor coupled between the input voltage terminal and the first amplifier output, and having a first control terminal;
• a second transistor coupled between the input voltage terminal and the output voltage terminal, and having a second control terminal coupled to the second amplifier output;
• a first offset voltage circuit having a first offset input and a first offset output, the first offset input coupled to the input voltage terminal;
• a second offset voltage circuit having a second offset input and a second offset output, the second offset input coupled to the input voltage terminal;
• a first comparator having first and second comparator inputs and a first comparator output, the first comparator input coupled to the first offset output, and the second comparator input coupled to the reference output;
• a second comparator having third and fourth comparator inputs and a second comparator output, the third comparator input coupled to the second offset output, and the fourth comparator input coupled to the output voltage terminal;
• an OR gate having first and second logic inputs and a logic output, the first logic input coupled to the first comparator output, and the second logic input coupled to the second comparator output;
• and
• a turn-off circuit having a turn-off input and a turn-off output, the turn-off input coupled to the logic output, and the turn-off circuit configured to provide a turn-off signal at the first control terminal in response to a logic high at the turn-off input.

A method for dampening overshoot in a voltage regulator, the method comprising:

• supplying an input voltage to a voltage regulator input and enabling a voltage regulator output;
• generating a reference voltage at a reference voltage output;
• regulating an output voltage at the voltage regulator output by comparing the reference voltage to a feedback voltage proportional to the output voltage;
• comparing a first offset voltage to a difference between the input voltage and the output voltage, and comparing a second offset voltage to a difference between the input voltage and the reference voltage;
• and
• disabling the voltage regulator output responsive to either the first offset voltage being greater than the difference between the input voltage and the output voltage, or the second offset voltage being greater than the difference between the input voltage and the reference voltage.