Patent ID: 6984969

Claim:
A voltage regulator, comprising: an output node which is at an output voltage V out (t); a linear mode voltage regulator which produces a first output voltage V ol (t) when activated in response to an input signal V i (t); a high pass filter circuit connected in series between V ol (t) and said output node and arranged to reduce the low frequency AC and DC currents provided by said linear mode regulator to said output node to substantially zero; a switch mode voltage regulator which produces a second output voltage V osw (t) when activated in response to an input signal V i (t); and a low pass filter circuit connected in series between V osw (t) and said output node and arranged to isolate high frequency AC current produced by said linear mode regulator from said switch mode regulator; such that, when activated, said linear mode regulator provides predominately high frequency AC current to said output node and said switch mode regulator provides predominately low frequency AC and DC currents to said output node, and both of said linear and switch mode regulators provide currents to said output node over a medium frequency range between said high and low frequencies, thereby providing said output voltage V out (t) at said output node.