Systems and methods providing active and passive charge sharing in a digital to analog converter

摘要

A method for converting a multi-bit digital value to an analog value. The method includes, in a first conversion cycle, converting a first set of digital bits to a first analog voltage using passive charge-sharing. The method also includes, in a second conversion cycle, converting a second set of digital bits to a second analog voltage added to the first analog voltage using active charge-sharing. The first set of digital bits and the second set of digital bits are different bits of the multi-bit digital value.

主权项

1. A method for converting a multi-bit digital value to an analog value using a Digital to Analog Converter (DAC) comprising a switched capacitor array, an amplifier, and at least one switch connected between the switched capacitor array and the amplifier, the method comprising:
in a first conversion cycle, converting a first set of digital bits to a first analog voltage using passive charge-sharing, wherein during the first conversion cycle the at least one switch is open to disconnect the amplifier from the switched capacitor array; and in a second conversion cycle, converting a second set of digital bits to a second analog voltage added to the first analog voltage using active charge-sharing, wherein during the second conversion cycle the at least one switch is closed to connect the amplifier to the switched capacitor array in a feedback configuration, wherein the first set of digital bits and the second set of digital bits are different bits of the multi-bit digital value, wherein the first set of digital bits comprises bits of lesser significance than the second set of digital bits, and wherein the second conversion cycle occurs after the first conversion cycle.