Voltage regulator with load pole stabilization

Abstract

A voltage regulator with load pole stabilization is disclosed. The voltage regulator consists of an error amplifier, an integrator which includes a switched capacitor, a pass transistor, and a feedback circuit. In one embodiment, the integrator circuit includes an amplifier, a capacitor, and a switched capacitor which is driven by a voltage controlled oscillator. The voltage controlled oscillator changes its frequency of oscillation proportional to the output current. In another embodiment, the switched capacitor is driven by a current controlled oscillator whose frequency of oscillation is also proportional to the output current of the voltage regulator. When the output current demand is large, the controlled oscillators increase the frequency which decreases the effective resistance of the switched capacitor thereby changing the frequency of the zero to respond to the change in the load pole. Conversely, the effective resistance is increased as the current demand is decreased, also to respond to the decrease in load pole. The controlled oscillator may be coupled to a current sensing device that generates a scaled version of the load current and couples to the regulated voltage output. The controlled oscillator is restricted to operating voltages that are related to the regulated output voltage and a control current that is a scaled version of the load current. Consequently, the disclosed voltage regulator has high stability without consuming excess power.

Dependencies are inferred from the claim text.