An audio DAC with 90 dB linearity using MOS to metal-metal charge transfer

Illustrates a technique for efficiently combining MOS capacitors and metal-metal capacitors in the design of switched-capacitor circuits. Switched-capacitor circuit architectures can generally be viewed as charge-based designs with voltage-to-charge conversion at their input and charge-to-voltage conversion at their output. By sharing charge between MOS capacitors having common node voltages and transferring that charge to or from metal-metal capacitors where charge-to-voltage conversion is needed, linearity can be maintained without an inordinate sacrifice in silicon area.