WM8190 Datasheet, PDF (1/25 Pages) Wolfson Microelectronics plc – (8+6) Bit Output 14-bit CIS/CCD AFE/Digitiser

WM8190
(8 + 6) Bit Output 14-bit CIS/CCD AFE/Digitiser
Advanced Information, August 1999, Rev 3.0
DESCRIPTION
The WM8190 is a 14-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 6MSPS.
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 14-bit
Analogue to Digital Converter. The digital output data is
available in 8, 7 or 4-bit wide multiplexed format, with no
missing codes.
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 WM8190 typically
only consumes 250mW when operating from a single
5V supply.
FEATURES
• 14-bit ADC
• No missing codes guaranteed
• 6MSPS conversion rate
• Low power – 250mW 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
• 8,7 or 4-bit wide multiplexed data output formats
• Internally generated voltage references
• 28-pin SOIC package
• Serial control interface
APPLICATIONS
• Flatbed and sheetfeed scanners
• USB compatible scanners
• Multi-function peripherals
• High-performance CCD sensor interface
BLOCK DIAGRAM
VRLC/VBIAS
(26)
VSMP MCLK
(5)
(7)
AVDD DVDD1 DVDD2
(21)
(3)
(10)
VRT VRX VRB
(24) (25) (23)
RINP (1)
GINP (28)
BINP (27)
CL
RLC
RLC
R_S V_S
M
U
X
TIMING CONTROL
CDS
R_{M 8}
GU
X
B
OFFSET
DAC
+ PGA
R_M
8
GU
X
B
VREF/BIAS
I/P SIGNAL
POLARITY
ADJUST
CDS
+ PGA
8
OFFSET
DAC
8
I/P SIGNAL
POLARITY
ADJUST
+
M
+U
X
WM8190
14-
BIT
ADC
DATA
I/O
PORT
(4) OEB
(13) OP[0]
(14) OP[1]
(15) OP[2]
(16) OP[3]
(17) OP[4]
(18) OP[5]
(19) OP[6]
(20) OP[7]/SDO
RLC
RLC ₄
DAC
CDS
+ PGA
+
8
OFFSET
DAC
8
I/P SIGNAL
POLARITY
ADJUST
CONFIGURABLE
SERIAL
CONTROL
INTERFACE
(9) SEN
(12) SCK
(11) SDI
(6) RLC/ACYC
(22)
AGND1
WOLFSON MICROELECTRONICS LTD
Lutton Court, Bernard Terrace, Edinburgh, EH8 9NX, UK
Tel: [phone]
Fax: [phone]
Email: [e-mail]
http://www.wolfson.co.uk
(2)
AGND2
(8)
DGND
Advanced Information data sheets contain
preliminary data on new products in the
preproduction phase of development.
Supplementary data will be published at a
later date.
©1999 Wolfson Microelectronics Ltd.