a

Complete 10-Bit 20 MSPS

CCD Signal Processor

 

 

 

 

 

AD9843A

 

 

 

FEATURES

20 MSPS Correlated Double Sampler (CDS)

4 dB 6 dB Variable CDS Gain with 6-Bit Resolution 2 dB to 36 dB 10-Bit Variable Gain Amplifier (VGA) Low Noise Clamp Circuits

Analog Preblanking Function

10-Bit 20 MSPS A/D Converter

Auxiliary Inputs with VGA and Input Clamp 3-Wire Serial Digital Interface

3 V Single Supply Operation

Low Power: 65 mW @ 2.7 V Supply 48-Lead LQFP Package

APPLICATIONS

Digital Still Cameras

Digital Video Camcorders

PC Cameras

PRODUCT DESCRIPTION

The AD9843A is a complete analog signal processor for CCD applications. It features a 20 MHz single-channel architecture designed to sample and condition the outputs of interlaced and progressive scan area CCD arrays. The AD9843A’s signal chain consists of an input clamp, correlated double sampler (CDS), digitally controlled variable gain amplifier (VGA), black level clamp, and 10-bit A/D converter. Additional input modes are provided for processing analog video signals.

The internal registers are programmed through a 3-wire serial digital interface. Programmable features include gain adjust- ment, black level adjustment, input configuration, and power- down modes.

The AD9843A operates from a single 3 V power supply, typi- cally dissipates 78 mW, and is packaged in a 48-lead LQFP.

FUNCTIONAL BLOCK DIAGRAM

PBLK

AVDD

 

AVSS

 

 

CLPOB

 

 

 

 

 

 

 

 

 

DRVDD

 

4dB

6dB

 

 

 

 

CLP

 

 

 

 

 

 

 

DRVSS

 

 

 

 

 

2dB~36dB

 

 

 

CDS

 

 

 

 

 

 

CCDIN

 

 

 

 

 

 

10

 

 

 

 

2:1

 

 

10-BIT

 

 

 

 

VGA

 

DOUT

 

 

 

 

MUX

 

ADC

 

 

 

 

 

 

 

 

CLP

 

 

 

 

 

 

 

CLPDM

 

 

 

 

 

 

BANDGAP

VRT

 

 

 

 

 

OFFSET

REFERENCE

VRB

 

 

 

 

 

10

AUX1IN

 

 

 

 

DAC

 

 

2:1

 

 

 

 

 

 

 

 

 

BUF

 

6

 

INTERNAL

 

 

MUX

 

 

 

CML

AUX2IN

 

 

 

 

 

8

BIAS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

INTERNAL

 

 

 

CLP

 

 

 

REGISTERS

 

 

 

 

 

 

 

 

 

 

 

DVDD

 

AD9843A

 

 

DIGITAL

 

INTERNAL

DVSS

 

 

INTERFACE

 

TIMING

SL

SCK SDATA

SHP

SHD DATACLK

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 which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781/329-4700

World Wide Web Site: http://www.analog.com

Fax: 781/326-8703

© Analog Devices, Inc., 2000

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Analog Devices AD9843A manual Product Description, Functional Block Diagram

AD9843A specifications

The Analog Devices AD9843A is a high-performance, integrated analog-to-digital converter (ADC) designed for a variety of applications requiring precise signal conversion. This device boasts a 12-bit resolution, making it suitable for capturing fine details in complex signals. The AD9843A operates with a maximum sampling rate of up to 130 MSPS (mega samples per second), which allows it to handle fast-changing waveforms effectively, ideal for applications in the fields of telecommunications, instrumentation, and medical imaging.

One of the standout features of the AD9843A is its dual-channel architecture, which enables simultaneous sampling of two input signals. This capability is particularly beneficial in applications such as radar and sonar systems, where capturing multiple input sources in parallel is critical. Furthermore, the ADC incorporates a high-speed programmable gain amplifier (PGA), providing adjustable gain settings to accommodate a wide range of signal amplitudes, ensuring optimal performance across various input conditions.

The AD9843A employs Differential Non-Linearity (DNL) and Integral Non-Linearity (INL) specifications, both of which contribute to its impressive accuracy and linearity. With a DNL of ±0.5 LSB (least significant bit) and an INL of ±1 LSB, the AD9843A minimizes distortion and enhances the fidelity of the digital representation of analog signals. Additionally, the device features low noise performance, which is essential for obtaining high-quality signal digitization, especially in sensitive applications where signal integrity is paramount.

Another key characteristic is the integrated sample-and-hold circuit that allows the ADC to capture input signals with minimal distortion during the conversion process. This design choice helps to stabilize the input signal, reducing the effect of sampling jitter. The AD9843A also provides various output data formats, including binary, gray code, and two's complement, which gives designers the flexibility to interface the ADC with different digital systems.

In terms of power consumption, the AD9843A is efficient, operating at a typical supply voltage of 5V. It offers a significant advantage for battery-operated devices by ensuring that the power requirements are kept low without compromising performance. With its combination of high throughput, low noise, and versatility, the Analog Devices AD9843A stands out as a robust solution for high-speed data acquisition systems, making it a preferred choice among engineers and designers across various industries.