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40MSPS 16-bit CCD Digitiser
DESCRIPTION
The WM8214 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 40MSPS.
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 16-bit
Analogue to Digital Converter. The digital output data is
available in 8-bit wide multiplexed format and there is also
an optional single byte output mode, or 4-bit multiplexed
LEGACY mode.
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.
Using an analogue supply voltage of 3.3V and a digital
interface supply of 3.3V, the WM8214 typically only
consumes 390mW.
WM8214
FEATURES
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16-bit ADC
40MSPS conversion rate
Low power – 390mW typical
3.3V single supply operation
Single, 2 or 3 channel operation
Correlated double sampling
Programmable gain (9-bit resolution)
Programmable offset adjust (8-bit resolution)
Flexible clamp control with programmable clamp voltage
Flexible timing, can be made compatible with WM819X
and WM815X parts.
8-bit wide multiplexed data output format
8-bit only output mode
4-bit LEGACY multiplexed nibble mode
Internally generated voltage references
28-pin SSOP package, pin compatible with WM8199
Serial control interface
APPLICATIONS
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High speed USB2.0 compatible scanners
Multi-function peripherals
High-performance CCD sensor interface
Digital Copiers
BLOCK DIAGRAM
VRLC/VBIAS
RSMP VSMP
MCLK
AVDD
DVDD1 DVDD2
VRT VRX VRB
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CLMP
R
S
V
S
TIMING CONTROL
R
G
B
M
U
X
8
WM8214
VREF/BIAS
OFFSET
DAC
+
PGA
9
OEB
+
I/P SIGNAL
POLARITY
ADJUST
M
U
X
16-
BIT
ADC
DATA
O/P
PORT
OP[0]
OP[1]
OP[2]
OP[3]
OP[4]
OP[5]
OP[6]
OP[7]/SDO
RINP
RLC
CDS
R
G
B
M
U
X
GINP
RLC
CDS
8
+
OFFSET
DAC
PGA
9
+
I/P SIGNAL
POLARITY
ADJUST
BINP
RLC
CDS
8
+
OFFSET
DAC
PGA
9
+
I/P SIGNAL
POLARITY
ADJUST
RLC
DAC
4
CONFIGURABLE
SERIAL
CONTROL
INTERFACE
SEN
SCK
SDI
AGND1
AGND2
DGND
WOLFSON MICROELECTRONICS plc
Product Preview, March 2004, Rev 1.6
w :: www.wolfsonmicro.com
Copyright
2004
Wolfson Microelectronics plc.
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
