Adaptive frequency compensation for high speed linear voltage regulator

摘要

In a linear voltage regulator, a first stage outputs an output signal. The first stage is configured with a first switchable bias current, and is configured to receive a feedback signal. A second stage provides a regulated voltage output. A decoupling capacitor is coupled to the regulated voltage output. A feedback circuit is coupled with the second stage and configured to generate the feedback signal. A frequency compensation circuit includes a second switchable bias current. The frequency compensation circuit: pushes away an existing pole to a higher frequency when the first and second switchable bias currents are operated in a sleep mode; and creates a left-hand-side zero when the first and second switchable bias currents are operated in an active mode. The active mode comprises the first and second switchable bias currents supplying greater currents than are provided in the sleep mode.

主权项

1. A linear voltage regulator comprising:
a first stage configured to output an output signal, wherein said first stage is configured with a first switchable bias current, and wherein said first stage is configured to receive a feedback signal; a second stage configured to provide a regulated voltage output; a decoupling capacitor coupled to said regulated voltage output of said second stage; a feedback circuit coupled with said second stage and configured to generate said feedback signal; and a frequency compensation circuit configured with a second switchable bias current, said frequency compensation circuit configured to:
push away an existing pole to a higher frequency when said first and second switchable bias currents are operated in a sleep mode; andcreate a left-hand-side zero when said first and second switchable bias currents are operated in an active mode, wherein said active mode comprises said first and second switchable bias currents supplying greater currents than are provided in said sleep mode.