Patent ID: 8022739

Claim:
A charge pump circuit comprising: a core charge pump circuit; a replica charge pump circuit for sensing a current mismatch in the core charge pump circuit and for converting the sensed current mismatch into a voltage signal V_ctrl; wherein V-ctrl is utilized for compensating the current mismatch in the core charge pump circuit; the core charge pump circuit includes a first n-type transistor and a first p-type transistor, parallel first and second branches between respective drains of the first n-type and the first p-type transistor, each branch including two switch elements, and a voltage follower circuit connected between a V ref input point and CP out point between the switch elements on the first and second branches respectively; the replica charge pump circuit includes a second n-type transistor and a second n-type transistor, two switch elements of the same type as the switch elements of the core charge pump circuit connected in series between the drains of the second n-type and the second p-type transistor; and a feedback loop with one input taken from a point between the two switch elements of the replica charge pump circuit and V ref supplied to another input of the feedback loop and V-ctrl as the output of the feedback loop; and further comprising a first current compensating circuit for converting V ctrl into a compensating “up” current, and a second current compensating circuit for converting V ctrl into a compensating “down” current.