Patent ID: 8736478

Claim:
Circuitry comprising a digital-to-analog converter (DAC) for converting a digital input value into a first analog output signal, the DAC comprising: a pulse-width encoder configured to generate a first charge pulse having a first pulse width proportional to the first digital input value; a first current source; a first capacitor configured to generate the first analog output signal; a first charging switch configured to selectively apply current from the first current source to the first capacitor based on the first charge pulse; and a first amplifier connected to the first capacitor in a negative feedback loop, wherein: the first charging switch selectively connects the first current source to a first plate of the first capacitor; the first analog output signal corresponds to a voltage level at a second plate of the first capacitor; an input of the first amplifier is connected to the first plate of the first capacitor; an output of the first amplifier is connected to the second plate of the first capacitor; and the first amplifier comprises: a PMOS device, whose channel is connected to the second plate of the first capacitor and whose gate is connected to a bias voltage; and an NMOS device, whose channel is connected to the second plate of the first capacitor and whose gate is connected to the first plate of the first capacitor.