WM8199
20MSPS 16-bit CCD Digitiser
DESCRIPTION
The WM8199 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 20MSPS.
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 or 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.
Using an analogue supply voltage of 5V and a digital
interface supply of either 5V or 3.3V, the WM8199 typically
only consumes 358mW when operating from a single
5V supply.
FEATURES
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16-bit ADC
20MSPS conversion rate
30MSPS conversion rate at 8-bits
Low power – 358mW typical
5V single supply or 5V/3.3V dual supply operation
Single or 3 channel operation
Correlated double sampling
Programmable gain (8-bit resolution)
Programmable offset adjust (8-bit resolution)
Programmable clamp voltage
8 or 4-bit wide multiplexed data output formats
Internally generated voltage references
28-pin SSOP package
Serial control interface
APPLICATIONS
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Flatbed and sheetfeed scanners
USB compatible scanners
Multi-function peripherals
High-performance CCD sensor interface
BLOCK DIAGRAM
VRLC/VBIAS
VSMP
MCLK
AVDD
DVDD1 DVDD2
VRT VRX VRB
w
CL
R
S
V
S
TIMING CONTROL
R
G
B
M
U
X
8
WM8199
VREF/BIAS
OFFSET
DAC
+
PGA
8
OEB
+
I/P SIGNAL
POLARITY
ADJUST
M
U
X
16-
BIT
ADC
DATA
I/O
PORT
OP[0]
OP[1]
OP[2]
OP[3]
OP[4]
OP[5]
OP[6]
OP[7]/SDO
RINP
RLC
M
U
X
CDS
R
G
B
M
U
X
GINP
RLC
CDS
8
+
OFFSET
DAC
PGA
8
+
I/P SIGNAL
POLARITY
ADJUST
BINP
RLC
CDS
8
+
OFFSET
DAC
PGA
8
+
I/P SIGNAL
POLARITY
ADJUST
RLC
DAC
4
CONFIGURABLE
SERIAL
CONTROL
INTERFACE
SEN
SCK
SDI
RLC/ACYC
AGND1
AGND2
DGND
WOLFSON MICROELECTRONICS plc
w :: www.wolfsonmicro.com
Production Data, November 2003, Rev 3.2
Copyright
2003
Wolfson Microelectronics plc
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
