the output node of output stage 365 is pulled high that is switch 415 and pull up transistor 365 a are configured to receive the control signal pg from the one shot circuit at substantially the same time to substantially synchronously close switch 415 and turn on pull up transistor 365 a control signal pg is also synchronously de asserted by the one shot circuit from switch 415 and pull up transistor 365 a providing synchronous operation of switch 410 and pull up transistor 365 a and synchronous operation of switch 415 and pull down transistor 365 b provides that the current icp sourced and u2212 icp sinked to and from the first input of second amplifier 350 will not introduce additional error into iin thereby not introducing additional error in vinp and will reduce vinp to substantially zero volts to compensate for fluctuations of vinp introduced by fluctuations of ifb that is by providing synchronous control of switch 415 and pull up transistor 365 a the temporal current profiles of u2212 icp and iin the current input into the first input of first amplifier 345 are substantially the same and by providing synchronous control of switch 410 and pull down transistor 365 b the temporal current.