WM8150_05 Datasheet, PDF (1/26 Pages) Wolfson Microelectronics plc – Single Channel 12-bit CIS/CCD AFE with 4-bit Wide Output

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WM8150
Single Channel 12-bit CIS/CCD AFE with 4-bit Wide Output
DESCRIPTION
The WM8150 is a 12-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 8MSPS.
The device includes a 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 12-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 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.
Using an analogue supply voltage of 5V, a digital core
voltage of 5V, and a digital interface supply of either 5V or
3.3V, the WM8150 typically only consumes 160mW when
operating from a single 5V supply.
BLOCK DIAGRAM
FEATURES
• 12-bit ADC
• 8MSPS conversion rate
• Low power - 170mW typical
• 5V single supply or 5V/3.3V dual supply operation
• Single channel operation
• 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-pin SSOP package
• Serial control interface
APPLICATIONS
• Flatbed and sheetfeed scanners
• USB compatible scanners
• Multi-function peripherals
• High-performance CCD sensor interface
VSMP MCLK
AVDD DVDD1 DVDD2
VRT VRX VRB
CL
R_S V_S TIMING CONTROL
VREF/BIAS
VINP
VRLC/VBIAS
RLC
CDS
RLC ⁴
DAC
WOLFSON MICROELECTRONICS plc
w :www.wolfsonmicro.com
R _{M 8 OFFSET}
GU
X
DAC
B
R_M
GU
X
B
+ PGA
+
I/P SIGNAL
8
POLARITY
ADJUST
W
WM8150
12-
BIT
ADC
DATA
I/O
PORT
OP[0]
OP[1]
OP[2]
OP[3]/SDO
CONFIGURABLE
SERIAL
CONTROL
INTERFACE
SEN
SCK
SDI
AGND1
AGND2
DGND
Production Data, February 2005, Rev 4.1
Copyright 2005 Wolfson Microelectronics plc