2-PHASE SWITCHED CAPACITOR FLASH ADC

摘要

An input stage for a switched capacitor analog-to-digital converter has a differential voltage input receiving an input voltage, a differential reference voltage input receiving a chopped reference voltage, a common voltage connection, and a differential output. A pair of input capacitors is coupled between the differential voltage input and the differential output and a pair of reference capacitors is coupled between the differential reference voltage input. A switching unit is controlled by a first and second phase operable during the first phase to connect a first terminal of the input capacitors with the common voltage connection and couple the first terminal of the reference capacitors with the inverted differential voltage reference; and during a second phase to connect the first terminal of the input capacitors with the differential input voltage and couple the first terminal of the reference capacitors with the non-inverted differential voltage reference

主权项

1. An input stage for a switched capacitor analog-to-digital converter, comprising:
a switching unit comprising a plurality of switching devices a differential voltage input receiving an input voltage; a differential reference voltage input receiving a chopped reference voltage; a common voltage connection; a differential output; a pair of input capacitors coupled between the differential voltage input and the differential output via a first switching device of the plurality of switching devices; a pair of reference capacitors coupled between the differential reference voltage input and the differential output via a second switching device of the plurality of switching devices; wherein the switching unit is controlled by a first and second phase and operable:
during the first phase to connect first terminals of the input capacitors via a third switching device of the plurality of switching devices with the common voltage connection and couple first terminals of the reference capacitors via the second switching device with an inverted chopped reference voltage ; andduring a second phase to connect the first terminals of the input capacitors via the first switching device with the input voltage and couple the first terminals of the reference capacitors with the non-inverted differential chopped reference voltage.