WM8259 Datasheet, PDF (1/26 Pages) Wolfson Microelectronics plc – Single Channel 16-bit CIS/CCD AFE with 4-bit Wide Output

w
WM8259
Single Channel 16-bit CIS/CCD AFE with 4-bit Wide Output
DESCRIPTION
The WM8259 is a 16-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 3MSPS.
The device has two selectable video input pins and one
complete analogue 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 Analogue 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 analogue supply voltage of 3.3V and a
digital interface supply of between 2.5V and 3.3V. The
WM8259 typically only consumes 132mW when operating
from a single 3.3V supply.
BLOCK DIAGRAM
FEATURES
• 16-bit ADC
• 3MSPS conversion rate
• Low power - 132mW typical
• 3.3V single supply or 3.3V/2.5V 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
APPLICATIONS
• Flatbed and sheetfeed scanners
• USB compatible scanners
• Multi-function peripherals
• High-performance CCD sensor interface
WOLFSON MICROELECTRONICS plc
To receive regular email updates, sign up at http://www.wolfsonmicro.com/enews/
Production Data, April 2007, Rev 4.2
Copyright ©2007 Wolfson Microelectronics plc