Low-Dropout Regulator with Pole-Zero Tracking Frequency Compensation

A method, comprising:

• providing current to a load using a first pass device and a second pass device coupled in parallel with each other and configured to operate simultaneously in a voltage regulator, wherein the first pass device provides a first current corresponding to a high-frequency component of the load current and the second pass device provides a second current corresponding to a low-frequency component of the load current;
• in response to a decrease in a low-frequency component of the first current during operation, causing the second current to decrease and causing the low-frequency component of the first current to increase;
• and
• in response to an increase in the low-frequency component of the first current during operation, causing the second current to increase and causing the low-frequency component of the first current to decrease;
• and
• comparing the magnitude of the first current to a magnitude of a reference current via a control loop.

A method, comprising:

• providing current to a load using a first pass device and a second pass device coupled in parallel with each other and configured to operate simultaneously in a voltage regulator, wherein the first pass device provides a first current corresponding to a high-frequency component of the load current and the second pass device provides a second current corresponding to a low-frequency component of the load current;
• in response to a decrease in a low-frequency component of the first current during operation, causing the second current to decrease and causing the low-frequency component of the first current to increase;
• and
• in response to an increase in the low-frequency component of the first current during operation, causing the second current to increase and causing the low-frequency component of the first current to decrease;
• and
• maintaining the magnitude of the low-frequency component of the first current equal to the magnitude of a reference current over time.

A voltage regulator, comprising:

• a first pass device configured to output a first current;
• and
• a second pass device coupled in parallel with the first pass device and configured to output a second current simultaneously with the first current, wherein the first current provides a high-frequency portion of a load current, and wherein the second current provides a low-frequency portion of the load current,
• wherein a control loop compares the low-frequency component of the first current to a magnitude of a reference current.