Analog Devices Inc. AD9842AJSTZ

Overview

AD9842AJSTZ from Analog Devices is a complete 12-bit, 20 MSPS CCD signal processor IC featuring correlated double sampling (CDS), 6-bit pixel gain amplifier (PxGA®), 10-bit variable gain amplifier (VGA) with 2 dB to 36 dB range, black level clamp, and integrated 3-wire serial interface - designed for high-fidelity analog signal conditioning in digital still cameras and camcorders.

For engineers reviewing the AD9842AJSTZ datasheet, AD9842AJSTZ pinout, AD9842AJSTZ application, or AD9842AJSTZ equivalent, key selection criteria include its 12-bit ADC resolution, 20 MHz maximum clock rate, LQFP-48 package compatibility, and support for CCD-mode timing with SHP/SHD sampling control and CLPOB/CLPDM clamping synchronization.

Technical Context

The AD9842AJSTZ implements a single-channel analog signal chain optimized for interlaced and progressive-scan area CCD arrays: input clamp → CDS → PxGA → VGA → black level clamp → 12-bit ADC. Its internal timing engine synchronizes SHP/SHD sampling edges with 3 ns aperture delay and supports seven programmable color steering modes for Bayer and multi-color filter arrays.

It operates from a single 3.0 V supply, dissipates 78 mW typical power, and uses a 3-wire serial interface (SCK/SL/SDATA) for register programming of gain, clamp level, channel mode (CCD/AUX1/AUX2), and power-down states - with fast recovery (<0.1 ms) from standby mode.

Key Specifications

Pinout & Package

AD9842AJSTZ is housed in a 48-lead thin plastic quad flatpack (LQFP-48), thermally rated at θ_JA = 92°C/W, with exposed pad not electrically connected. Pin 1 identifier located top-left; pins 1–12 and 41–48 assigned as digital I/O, pins 25–27/33/35/40 as analog/digital ground and supply rails, and pins 30/34/36 as analog inputs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar CCD signal processor applications.

Compared with AD9841AJSTZ and TDA8785HN/N1/C1, AD9842AJSTZ delivers higher resolution digitization, finer black level control, and native CCD timing support - making it optimal for 12-bit scientific, medical, and premium consumer imaging where pixel-level gain correction and noise performance are critical.

Availability

AD9842AJSTZ is available at Aetrix Electronics and suitable for digital still cameras, industrial inspection systems, and medical endoscopy modules requiring stable component supply, long-term lifecycle support, and traceable sourcing for Class II medical and automotive-qualified designs.

Supply support for AD9842AJSTZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies, serving industrial, communications, automotive, and healthcare markets since 1965.

The AD984x family was engineered specifically for CCD-based imaging systems, integrating precision analog signal conditioning, pixel-level gain control, and timing-critical sampling functions into a single 3 V, low-power IC - targeting compact, high-fidelity camera modules.

FAQ

What is the ADC resolution of the AD9842AJSTZ?

The AD9842AJSTZ features a true 12-bit analog-to-digital converter with guaranteed no-missing-codes performance and ±0.5 LSB differential nonlinearity. This resolution is confirmed in the AD9842A CCD-mode specifications table and distinguishes it from the 10-bit AD9841A variant. The AD9842AJSTZ achieves this using a fully differential pipeline architecture optimized for CCD signal bandwidth and noise floor requirements.

Does the AD9842AJSTZ support multiple CCD timing modes?

Yes, the AD9842AJSTZ supports three primary input modes: CCD-mode (with SHP/SHD sampling and CLPOB/CLPDM clamping), AUX1-mode, and AUX2-mode - each with distinct VGA gain ranges and power profiles. Timing diagrams for all modes are provided in Figures 5–7 of the datasheet, and the mode is selected via the Channel Select bits in the Operation Register (Address 000).

How does the PxGA function in the AD9842AJSTZ?

The PxGA in the AD9842AJSTZ is a 6-bit pixel gain amplifier offering four independently programmable gain values (Gain0–Gain3), sequenced via seven color steering modes including Mosaic Separate (Bayer), Interlace, and 4-Color. It operates upstream of the VGA to correct per-pixel sensitivity variations before analog amplification, directly improving white balance accuracy and reducing downstream digital processing load in the AD9842AJSTZ signal chain.

What is the power consumption of the AD9842AJSTZ under normal operation?

The AD9842AJSTZ consumes 78 mW typical power at 3.0 V supply and 20 MHz DATACLK frequency, as specified in the General Specifications table. Power varies with clock rate (TPC 1) and operating mode: AUX1/AUX2 modes draw ~60 mW, while fast recovery standby draws 30 mW and total shutdown draws 1 mW - all confirmed in the AD9842A CCD-mode specifications section.

Is the AD9842AJSTZ pin-compatible with the AD9841AJSTZ?

Yes, the AD9842AJSTZ is pin-compatible with the AD9841AJSTZ in the 48-lead LQFP package (ST-48). Both share identical pin functions, power domains, and serial interface layout; the only physical difference is that AD9842AJSTZ outputs D0–D11 (12-bit) on pins 1–12, whereas AD9841AJSTZ outputs D0–D9 (10-bit) on the same pins - with pins 11–12 unused (NC) in the AD9841A variant.