Conversion Errors in 4-Bit Flash Analog-to-Digital Converters

Conversion errors in 4-bit flash analog-to-digital converters are computed from difference equations as a function of the ratio of the comparator input impedance to the R-2R bias network values. For maximum conversion errors less than 3 percent, the comparator input impedance should be 1000 times greater than the R value of the bias network.