| 摘要 |
A DAC circuit 500 comprises positive and negative signal processing devices 500a,b each with a feedback capacitor 104a,b and each having a second capacitor 106a,b switchably couplable to a reference source for charging and switchably couplable to dump charge to a said feedback capacitor 104a,b of the positive or negative signal processing device 500a,b. A method of operating the differential digital-to-analogue (DAC) circuit to reduce signal dependent loading of a reference source associated with the DAC circuit, comprises repeatedly coupling said second capacitors to said reference source for charging and coupling said second capacitors to alternate ones of said positive and negative devices for dumping stored charge to a respective feedback capacitor; such that on average over a plurality of charge-dump cycles charge loading of said reference source by said DAC circuit is substantially constant.
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