Digital-to-analog converter (dac) termination

A digital-to-analog converter (DAC) circuit with multiple parallel impedance networks, the DAC circuit comprising:

• a pair of voltage reference nodes for applying different voltage levels;
• a first termination impedance path, comprising at least a first termination impedance element and a second termination impedance element, the first termination impedance path coupled between the voltage reference nodes
• a second termination impedance path, comprising at least a third termination impedance element and a fourth termination impedance element, the second termination impedance path coupled between the voltage reference nodes and in shunt with the first termination impedance path;
• a first plurality of impedance elements arranged in an impedance string for coupling between the first termination impedance path and the second termination impedance path, to generate a plurality of voltage signals;
• and
• a switching network configured to receive a digital signal and, in response, selectively couple one or more of the plurality of generated voltage signals to generate a combined analog voltage DAC output signal, the DAC output signal providing an analog representation of the digital signal.

A method for reducing alternating current (AC) impedance of a digital-to-analog converter (DAC) circuit, the method comprising:

• configuring via switching circuitry, an impedance string to receive a first voltage reference signal of a pair of voltage reference signals via a first termination impedance element of a termination impedance path, to reduce a first AC termination impedance of the impedance string;
• configuring via the switching circuitry, the impedance string to receive, a second voltage reference signal of the pair of voltage reference signals while coupled in shunt with a second termination impedance element of the termination impedance path, to reduce a second AC termination impedance of the impedance string during a shunt AC operation mode;
• generating a plurality of voltage reference signals in response to applying the first voltage reference signal and the second voltage reference signal;
• receiving a digital signal comprising digital data;
• and
• in response to the digital signal, selectively coupling one or more of the plurality of generated voltage signals to generate a combined analog voltage DAC output signal providing an analog representation of the digital signal.