WM8191

WM8191 14-bit 6MSPS CIS/CCD Analogue Front End/Digitiser Advanced Information, April 2001, Rev 3.1 DESCRIPTION The WM8191 is a 14-bit analogue front end/digitiser IC which processes and digitises the analogue output signals from CCD sensors or Contact Image Sensors (CIS) at pixel sample rates of up to 6MSPS. The device includes three analogue signal processing channels each of which contains Reset Level Clamping, Correlated Double Sampling and Programmable Gain and Offset adjust functions. Three multiplexers allow single channel processing. The output from each of these channels is time multiplexed into a single high-speed 14-bit analogue-to-digital converter. The digital output data is available in 14-bit parallel or 8/7/4-bit wide multiplexed format, with no missing codes. An internal 4-bit DAC is supplied for internal reference level generation. This may be used during CDS to reference CIS signals or during Reset Level Clamping to clamp CCD signals. Alternatively an external reference level may be applied. ADC references are generated internally, ensuring optimum performance from the device. Using an analogue supply voltage of 5V and a digital interface supply of either 5V or 3.3V, the WM8191 typically only consumes 250mW when operating from a single 5V supply and less than 1µA when in power down mode. FEATURES 14-bit ADC No missing codes guaranteed 6MSPS conversion rate Low power – 250mW typical 5V single supply or 5V/3.3V dual supply operation Single or 3 c...