Digital-to-analog converter with digital charge sharing components

摘要

A method and a digital-to-analog converter (DAC) circuit involve forming an analog signal using charge sharing operations. The DAC circuit includes a plurality of digital components with associated parasitic capacitances. The digital components are activated based on a digital input code, such that charge is shared among the parasitic capacitances to form a first analog signal proportional to the digital input code. The digital components can also be activated based on a complementary code to form a second analog signal. The first analog signal and the second analog signal can be used to form, as a final output of the DAC circuit, an analog signal that is linearly proportional to the digital input code.

主权项

1. A digital-to-analog converter (DAC) circuit that forms an analog signal using charge sharing operations, the DAC circuit comprising:
a plurality of digital components with associated parasitic capacitances, wherein the digital components include a parallel arrangement of FET inverters located between a charge redistribution node, providing a DAC analog output signal, and a first reference voltage node; and a main capacitor, located in parallel with the FET inverters between the charge redistribution node and the first reference voltage node, wherein the main capacitor is charged using a second reference voltage prior to the activation of the digital components, wherein the activation moves charge on the charge redistribution node from the main capacitor to the parasitic capacitances associated with the activated digital components; wherein the digital components are activated, based on a digital input code, such that charge is shared among the parasitic capacitances to form a first analog signal proportional to the digital input code.