Single Channel CCD/CIS ADC

The WM8259 is a 16-bit analog front end/digitizer IC which processes and digitizes the analog output signals from CCD sensors or Contact Image Sensors (CIS) at pixel sample rates of up to 3 MSPS. The device has two selectable video input pins and one complete analog signal processing channel containing reset level clamping, correlated double sampling, programmable gain and offset adjust functions. Internal multiplexers allow fast switching of offset and gain for line-by-line colour processing. The output from this channel is time multiplexed into a high-speed 16-bit analog to digital converter. The digital output data is available in 4-bit wide multiplexed format. 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. An external reference level may also be supplied. ADC references are generated internally, ensuring optimum performance from the device. The device uses an analog supply voltage of 3.3 V and a digital interface supply of between 2.5 V and 3.3 V. The WM8259 typically only consumes 132 mW when operating from a single 3.3 V supply.


Imaging A/D Converters


  • 16-bit ADC
  • 3 MSPS conversion rate
  • Low power - 132 mW typical
  • 3.3 V single supply or 3.3/2.5 V dual supply operation
  • Single channel operation, selectable inputs
  • Correlated double sampling
  • Programmable gain (8-bit resolution)
  • Programmable offset adjust (8-bit resolution)
  • Programmable clamp voltage
  • 4-bit wide multiplexed data output format
  • Internally generated voltage references
  • 20-lead SSOP package
  • Serial control interface

Parametric Specifications

Resolution (bits) 16
Speed (MSPS) 3
Input PGA (bits) 8
Output Format 4+4+4+4 bit (nibble)
Supply (V) 2.97-3.63
Power Consumption (mW) 132
Package 20 SSOP


Comprehensive Solutions