AD9840AJST

Overview

The AD9840AJST is a complete analog signal processor for CCD applications, featuring a 40 MHz single-channel architecture. It includes an input clamp, correlated double sampler (CDS), variable gain amplifier (VGA), black level clamp, and a 10-bit A/D converter. The device operates from a 3 V supply with typical power consumption of 155 mW. Key specifications include a maximum clock rate of 40 MHz, 10-bit resolution, and a CDS gain range of -2 dB to +10 dB. The VGA provides 2 dB to 36 dB gain with 10-bit resolution. It utilizes a 3-wire serial interface for register programming and is housed in a 48-lead LQFP package.

Feature Summary

• Integrated 40 MSPS Correlated Double Sampler with programmable gain
• 10-Bit Variable Gain Amplifier offering wide dynamic range adjustment
• Low noise clamp circuits for optical black and input offset correction
• 3-Wire Serial Digital Interface for internal register configuration

Applications

• Digital Video Camcorders
• Digital Still Cameras
• Industrial Imaging

Procurement Notes

Verify the specific suffix ST against the manufacturer's current ordering guide to confirm package type and temperature range compatibility. Ensure that the lead time and availability status are checked directly with authorized distributors or the manufacturer, as these details are subject to change and not included in this technical summary.

Selection Notes

Select the AD9840AJST for systems requiring a single-chip solution for CCD signal conditioning up to 40 MHz. Consider the 10-bit ADC resolution and the specific gain ranges of the CDS and VGA stages when matching input signal levels. Verify that the 3 V single-supply operation aligns with the system power budget and that the LQFP-48 package fits the PCB layout constraints.

Part Context

The AD9840A belongs to Analog Devices' family of CCD signal processors designed for image capture applications. It serves as an analog front-end component that bridges CCD sensors and digital processing units. The AJST variant specifically denotes the industrial temperature range (-20°C to +85°C) and the thin plastic quad flatpack package option within the broader AD9840A product line.

Replacement Considerations

Public confirmed substitute part numbers: None identified.