Complete 14-Bit, 56 MSPS
Imaging Signal Processor
AD9941
FEATURES
GENERAL DESCRIPTION
Differential sensor input with 1 V p-p input range
0 dB/6 dB variable gain amplifier (VGA)
Low noise optical black clamp circuit
14-bit, 56 MSPS analog-to-digital converter (ADC)
No missing codes guaranteed
3-wire serial digital interface
3 V single-supply operation
Low power CMOS: 145 mW @ 3.0 V, 56 MHz
48-lead LQFP package
The AD9941 is a complete analog signal processor for imaging
applications that do not require correlated double sampling
(CDS). It is also suitable for processing the output signal from
the AD9940 CDS front end product. It features a 56 MHz, single-
channel architecture designed to sample and condition the output
of CMOS imagers and CCD arrays already containing on-chip
CDS. The AD9941 signal chain consists of a differential input
sample-and-hold amplifier (SHA), a digitally controlled variable
gain amplifier (VGA), a black level clamp, and a 14-bit ADC.
The internal registers are programmed through a 3-wire serial
digital interface.
APPLICATIONS
Digital still cameras using CMOS imagers
Professional HDTV camcorders
Professional/high-end digital cameras
Broadcast cameras
The AD9941 operates from a single 3 V supply, typically
dissipates 145 mW, and is packaged in a 48-lead LQFP.
FUNCTIONAL BLOCK DIAGRAM
AVDD AVSS
REFT REFB
PBLK
AD9941
DRVDD
DRVSS
BAND GAP
REFERENCE
0dB, 6dB
VGA
VIN+
VIN–
14
14-BIT
ADC
DOUT
SHA
CLP
CLPOB
8
INTERNAL
REGISTERS
BLK CLAMP
LEVEL
DVDD
DVSS
DIGITAL
INTERFACE
SL
SCK
SDATA
ADCLK
Figure 1.
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
www.analog.com
© 2005 Analog Devices, Inc. All rights reserved.