Voltage regulator stabilization for operation with a wide range of output capacitances

摘要

A voltage regulator includes a measurement circuit for obtaining a value representing a magnitude of an output capacitance connected at an output node of the voltage regulator. A correction circuit in the voltage regulator modifies a compensation circuit internal to the voltage regulator based on the value. The modification of the compensation circuit is done to ensure that sufficient stability margins to accommodate the output capacitance are ensured for the main feedback loop in the voltage regulator. In an embodiment, a voltage proportional to the output capacitance is detected at start-up of the voltage regulator, and a corresponding binary signal is generated. The logic value of the binary signal is used to add or remove components and/or circuit portions in the compensation circuit to ensure stability. The voltage regulator is thus designed to support a wide range of output capacitance values.

主权项

1. A voltage regulator comprising:
a measurement circuit for generating a value representing a magnitude of a capacitance at an output node of the voltage regulator; and a correction circuit for modifying, based on the value, a compensation circuit internal to the voltage regulator comprising resistance and capacitance and having a zero corresponding to a frequency substantially equal to (1/(2π(the resistance being total resistance of internal wiring of an integrated ciruit and the equivalent series resistance of the output capacitor)(the capacitance being capacitance of the output capacitor)) the correction circuit modifying a closed-loop feedback circuit by increasing a frequency of the zero in the closed feedback loop of the voltage regulator by changing values of the resistance or the capacitance in the feedback loop to provide stability to the closed feedback loop.