Synaptics Incorporated
Linear regulator with first and second feedback voltages

Abstract:

A voltage regulation system includes an error amplifier configured to generate an error amplifier output based on a reference voltage, input voltage, first feedback voltage, and second feedback voltage. The feedback voltages are based on a first output voltage at the system's output node. The system further includes a capacitor configured to provide the first feedback voltage to the error amplifier. The system further includes a voltage-controlled current source configured to generate a current based on the first output voltage. The second feedback voltage is based on the current. The system further includes a transistor configured to provide a second output voltage at the output node based on the error amplifier output. The transistor is connected to the output node and the capacitor. Such a voltage regulation system may allow a high power supply rejection response over a wide range of frequencies and loads while maintaining stability and phase margin.