WM8191

The WM8191 is a 14-bit analogue front end/digitiser ICwhich processes and digitises the analogue output signalsfrom CCD sensors or Contact Image Sensors (CIS) at pixelsample rates of up to 6MSPS.

The WM8191 includes three analogue signal processingchannels each of which contains Reset Level Clamping,Correlated Double Sampling and Programmable Gain andOffset adjust functions. Three multiplexers allow singlechannel processing. The output from each of thesechannels is time multiplexed into a single high-speed 14-bitanalogue-to-digital converter. The digital output data isavailable in 14-bit parallel or 8/7/4-bit wide multiplexedformat, with no missing codes.

An internal 4-bit DAC of the WM8191 is supplied for internal reference levelgeneration. This may be used during CDS to reference CISsignals or during Reset Level Clamping to clamp CCsignals. Alternatively an external reference level may beapplied. ADC references are generated internally, ensuringoptimum performance from the device.

Using an analogue supply voltage of 5V and a digitalinterface supply of either 5V or 3.3V, the WM8191 typicallyonly consumes 250mW when operating from a single 5Vsupply and less than 1A when in power down mode.