SUPPLY-SIDE VOLTAGE REGULATOR

摘要

A voltage regulator generates an output voltage that is a designed voltage level below the supply voltage. A reference voltage generator generates a reference voltage between ground and supply voltages. A voltage divider generates a feedback voltage between the supply and output voltages. An amplifier generates an amplifier output voltage based on a difference between the reference and feedback voltages. A buffer buffers the amplifier output voltage. A pass transistor receives the buffered voltage at its control node to sink an average load current appearing at the output node. A capacitor is connected between the supply and output voltages to provide a peak load current. A load-current-detecting transistor receives the buffered voltage at its control node to sense the load current. A compensation transistor compensates for leakage current. An internal load converts the sensed load current into a voltage control signal applied to the compensation transistor.

主权项

1. A voltage regulator that generates, at an output node, an output voltage that is a designed voltage level below a supply voltage for the voltage regulator, the voltage regulator comprising:
a reference voltage generator that receives the supply voltage and a ground voltage and generates a reference voltage between the ground and supply voltages; a voltage divider connected between the supply voltage and the output voltage to generate a feedback voltage between the supply voltage and the output voltage; an amplifier connected to receive the reference voltage and the feedback voltage and generate an amplifier output voltage based on a difference between the reference voltage and the feedback voltage; a buffer connected to receive the amplifier output voltage and generate a buffered voltage; a pass transistor connected between the output voltage and the ground voltage, and connected to receive the buffered voltage at its control node to sink an average load current appearing at the output node; a capacitor connected between the supply and output voltages to provide a peak load current at the output node; a load-current-detecting transistor connected between the supply and ground voltages and connected to receive the buffered voltage at its control node to sense the load current appearing at the output node; a compensation transistor connected between the supply and output voltages to compensate for leakage current between the output and ground voltages resulting from a leakage-current path downstream of the output node; and an internal load connected in series with the load-current-detecting transistor between the supply and ground voltages to convert the sensed load current into a voltage control signal applied to the control node of the compensation transistor.