| 摘要 |
Currently available flash-type analog-to-digital converters (ADCs) use large quantities of voltage comparators, resistors and logic gates. An 8-bit flash ADC uses 255 comparators, 256 resistors, and a large number of logic gates in the priority encoder which is connected at the comparator outputs. This invention results in an 8-bit ADC that produces the digital output right at the output terminals of 8 voltage comparators. No priority encoder is needed, and therefore no logic gates are required. As well as the 8 voltage comparators, 8 operational amplifiers and 53 resistors are required for an 8-bit version of this new type of ADC. The circuit operates by setting the bias voltage levels for the comparators by means of digital-to-analog converters (DACs). The inputs to each DAC are a reference voltage level and the higher order digital outputs. Substantial component savings are effected for ADCs with any number of output bits. |
