Patent ID: 8089261

Claim:
A method of stabilizing a feedback control loop in a low dropout voltage regulator comprising: detecting changes in a gate voltage at a gate of a pass transistor that results from changes in load current flowing in a load that is driven by said pass transistor; controlling a current mirror ratio of a current mirror based upon said changes in said gate voltage; detecting an output voltage that is applied to said load; controlling current flow in said first leg of a load current tracking zero circuit, connected to said current mirror, by applying said output voltage to a gate of a source follower buffer disposed in said first leg; generating current flow in a second leg of said load current tracking zero circuit, connected to said current mirror, that is a mirror of said current flow in said first circuit, but that is amplified by said current mirror ratio; extracting a bias current component of said current flow in said second leg of said circuit, which is equal to a bias current generated in said first leg multiplied by said current mirror ratio, to generate an error current signal that varies with said load current; applying said error current signal to said feedback control loop to provide a current signal that generates a zero current in said feedback loop to stabilize said feedback loop.