AD9843AJST

Overview

The AD9843AJST is a complete analog signal processor for CCD applications, featuring a 20 MHz single-channel architecture. It samples and conditions outputs of interlaced and progressive scan area CCD arrays. The signal chain includes an input clamp, correlated double sampler (CDS), digitally controlled variable gain amplifier (VGA), black level clamp, and a 10-bit A/D converter. Operating from a single 3 V supply, it dissipates 78 mW in normal operation. Key parameters include a 20 MSPS maximum clock rate, 10-bit resolution with no missing codes, and a 2.0 V full-scale input voltage. It supports a 3-wire serial digital interface for register programming.

Feature Summary

• Integrates a 20 MSPS Correlated Double Sampler (CDS) with programmable gain ranging from -2 dB to +10 dB.
• Includes a Variable Gain Amplifier (VGA) providing a gain range of 2 dB to 36 dB with 10-bit resolution control.
• Features low noise clamp circuits and an analog preblanking function for accurate black level correction.
• Supports auxiliary input modes for processing analog video signals with dedicated VGA and input clamp capabilities.

Applications

• Digital Still Cameras
• Digital Video Camcorders
• PC Cameras

Procurement Notes

Verify the specific ordering suffix 'JST' corresponds to the Thin Plastic ST-48 Quad Flatpack (LQFP) package and the -20°C to +85°C operating temperature range as defined in the Analog Devices Ordering Guide. Confirm that the component meets RoHS compliance requirements for the intended market. Ensure proper ESD precautions are observed during handling due to the device's sensitivity to electrostatic discharge.

Selection Notes

Select this component when interfacing with interlaced or progressive scan area CCD arrays requiring a single-channel solution. It is suitable for systems needing integrated DC restoration, CDS, and VGA functions within a 3 V single-supply design. Consider the 48-lead LQFP package constraints and the requirement for a 3-wire serial interface for configuration. Evaluate power consumption needs against the 78 mW typical dissipation at 3.0 V.

Part Context

The AD9843A belongs to the AD9841A series of CCD signal processors from Analog Devices. It shares architectural similarities with other members like the AD9841A but is optimized for 20 MSPS performance. The 'JST' suffix denotes the specific tape-and-reel or tray packaging variant available in the standard commercial temperature grade. This part serves as a direct replacement for legacy CCD front-end designs requiring high integration.

Replacement Considerations

Public confirmed substitute part numbers: AD9843A JST.