US Patent 7119730 Analog-to-digital converter for programmable logic

Digital-to-analog and analog-to-digital conversion are implemented in or using programmable logic. The DAC and ADC circuits may be hardwired in a programmable logic integrated circuit or may be implemented using an intellectual property (IP) core. The IP core would be a series of bits to configure the logic cells and other programmable logic of an integrated circuit to include one or more DACs or ADC, or both on the same integrated circuit. The DAC may be a sigma-delta-modulator-based implementation or a resistor-ladder-based implementation.