Launched in early 1999, the new ADC12181 high-speed A / D converter is suitable for applications in image processing, data acquisition for PCs, scanners and waveform scanners. An important feature of National's ADC12181 is the inclusion of an internal sampling and retention circuit that makes design easier. In the application circuit shown in figure 1 all voltages must be applied simultaneously. As it comes to high speed circuit it is very important to be careful with the layout of the signal lines. An important precaution in this application is that both the ground for the digital and analog signals are on the same levels, avoiding the capacitive coupling between them. The voltage reference is given by an LM4041 IC, and the high speed operational amplifier LM6181 couples the external signal source to the input converter circuit.
