Complete 14-Bit, 56 MSPS Imaging Signal Processor AD9941 FEATURES GENERAL DESCRIPTION Differential sensor input with 1 V p-p input range The AD9941 is a complete analog signal processor for imaging 0 dB/6 dB variable gain amplifier (VGA) applications that do not require correlated double sampling Low noise optical black clamp circuit (CDS). It is also suitable for processing the output signal from 14-bit, 56 MSPS analog-to-digital converter (ADC) the AD9940 CDS front end product. It features a 56 MHz, single- No missing codes guaranteed channel architecture designed to sample and condition the output 3-wire serial digital interface of CMOS imagers and CCD arrays already containing on-chip 3 V single-supply operation CDS. The AD9941 signal chain consists of a differential input Low power CMOS: 145 mW 3.0 V, 56 MHz sample-and-hold amplifier (SHA), a digitally controlled variable 48-lead LQFP package gain amplifier (VGA), a black level clamp, and a 14-bit ADC. The internal registers are programmed through a 3-wire serial APPLICATIONS digital interface. Digital still cameras using CMOS imagers Professional HDTV camcorders The AD9941 operates from a single 3 V supply, typically Professional/high-end digital cameras dissipates 145 mW, and is packaged in a 48-lead LQFP. Broadcast cameras FUNCTIONAL BLOCK DIAGRAM AVDD AVSS REFT REFB PBLK AD9941 DRVDD BAND GAP REFERENCE DRVSS 0dB, 6dB VIN+ 14 14-BIT DOUT VGA SHA ADC VIN CLP CLPOB 8 INTERNAL BLK CLAMP REGISTERS LEVEL DVDD DIGITAL INTERFACE DVSS 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. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Specifications subject to change without notice. No license is granted by implication Tel: 781.329.4700 www.analog.com or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Fax: 781.461.3113 2005 Analog Devices, Inc. All rights reserved. 05504-001 AD9941 TABLE OF CONTENTS Specifications .....................................................................................3 Equivalent Input/Output Circuits...................................................9 Digital Specifications ....................................................................3 Serial Interface Timing...................................................................10 Analog Specifications ...................................................................4 Circuit Description and Operation ..............................................12 Timing Specifications ...................................................................5 Differential Input SHA ...............................................................12 Timing Diagrams ..........................................................................5 Variable Gain Amplifier.............................................................13 Absolute Maximum Ratings ............................................................6 ADC..............................................................................................13 Thermal Characteristics...............................................................6 Optical Black Clamp...................................................................13 ESD Caution ..................................................................................6 Applications Information...............................................................14 Pin Configuration and Function Descriptions .............................7 Outline Dimensions........................................................................16 Terminology.......................................................................................8 Ordering Guide ...........................................................................16 REVISION HISTORY 7/05Revision 0: Initial Version Rev. 0 Page 2 of 16