Charge pump circuit and method

摘要

A charge pump circuit (20, 30) comprising: a first operational amplifier (230, 330) having a first input node (221, 321), a second input node (222, 322) and an output node (220, 320), said first operational amplifier (230, 330) being configured for adjusting the voltage at said output node (220, 320) to a reference value provided at said first input node (221, 321); a first current source (210, 310) and a second current source (211, 311) for providing respective first (I 210 , I 211 ) and second (I 310 , I 311 ) currents to said second input node (222, 322); a first switch (200, 300) and a second switch (201, 301) respectively configured for determining the amount of current (I 210 , I 211 ; I 310 , I 311 ) delivered to said second input node (222, 322); a loop filter (250, 350) configured for receiving a current difference between said first (I 210 , I 211 ) and second (I 310 , I 311 ) currents provided at said second input node (222, 322). It further comprises an automatic calibration circuit (280, 380) configured for directly controlling the current (I 210 , I 310 ) provided by said first current source (210, 310). Method of calibrating a charge pump circuit (20, 30).