Demonstration circuit DC890B along with QuickEval- II™ software provides a USB based Windows PC hosted digital data acquisition system supporting CMOS/LVDS output ADCs up to 250Msps. The DC890B must be powered from an external 6±0.5VDC power supply when operating in LVDS mode. When operating in CMOS mode, the external power supply is optional. The Linear Technology supplied QuickEval-II evaluation software automatically detects the DC890B and can also detect many of the standard ADC demonstration circuits boards. The DC890B will not enable LVDS mode unless an external 6.0VDC power source is available. The QuickEval-II system provides for fast and easy performance evaluation of high speed ADCs. FastDAACS collects up to 256K word samples and then performs various analyses on the data including calculating SNR, SINAD, THD, SFDR and ENOB. The digitized input, an FFT of the collected data, the Primitive Wave of the sample set or a IFFT of modified frequency domain data is plotted to a display window to facilitate analyzing distortion products and sources. Figure 1 shows a picture of the DC890B. The DC890B is connected to the ADC demonstration circuit via a 100 pin edge connector, to the PC by a USB A-B cable and to an optional power supply either by a 5mm power plug or optionally by turrets. Figure 2 details the connections.