Patent ID: 7659703

Claim:
An apparatus for providing at least one pole and at least one zero with independent pole and zero frequency separation, comprising: an error amplifier having at least a first input that is coupled to a reference node, a second input that is coupled to a feedback node, and an output that is coupled to a control node; a first circuit that is arranged to provide a first current to the feedback node based, at least in part, on a voltage at an output node; and a second circuit that is arranged to provide a second current to the feedback node based, at least in part, on a voltage at the output node, wherein the first circuit and the second circuit are arranged to provide a zero at a first frequency and to provide a pole at a second frequency, wherein a closed loop transfer function V fb (s) is given by: V fb ⁡ ( s ) = K · 1 + R 0 ⁢ C 0 ⁡ ( 1 + g m ⁢ R 1 ) ⁢ s 1 + R 0 ⁢ C 0 ⁢ s ⁢ V o ⁡ ( s ) wherein R 1 is a value of a first resistance associated with the first circuit, gm is a value of a transconductance associated with the first circuit, R 0 is a value of a resistance associated with the second circuit, C 0 is a value of a capacitance associated with the second circuit, and K is the gain of the error amplifier, and wherein the first circuit and the second circuit are further arranged to provide independent control of the location of the zero and the location of the pole.