ANALOG DEVICES AD9978A Service Manual

Dual-Channel, 14-Bit HD Image Signal

FEATURES

Dual AFE channels

1.8 V analog and digital core supply voltage
Serial data output with reduced range LVDS outputs
Differential analog inputs
CDS or SHA configuration (CDS bypass) with

−3 dB, 0 dB, +3 dB, and +6 dB gain
6 dB to 42 dB, 10-bit variable gain amplifier (VGA)
14-bit, 75 MHz analog-to-digital converter (ADC)
Black level clamp with variable level control
Precision Timing core with 210 ps resolution @ 75 MHz

APPLICATIONS

Digital video cameras
Digital still cameras
Digital copiers
Multifunction printers
High speed industrial cameras

Processor with Precision Timing Core

AD9978A

GENERAL DESCRIPTION

The AD9978A is a highly integrated, dual-channel, charge­coupled device (CCD) signal processor for high speed digital
video camera applications. Each channel is specified at pixel
rates of up to 75 MHz and consists of a complete analog front
end (AFE) with ADC conversion. The Precision Timing™ core
allows adjustment of the correlated double sampler (CDS) and
sample-and-hold amplifier (SHA) clocks with 210 ps resolution at
75 MHz operation. The AD9978A also contains a reduced range
low voltage differential signaling (LVDS) interface for the dual­channel data outputs.

Each analog front end includes black level clamping, a CDS,
a VGA, and a 75 MHz, 14-bit analog-to-digital converter (ADC).
Operation is programmed using a 3-wire serial interface.

Packaged in a space-saving, 6 mm × 6 mm, 40-lead LFCSP, the
AD9978A is specified over an operating temperature range of

−25°C to +85°C.

FUNCTIONAL BLOCK DIAGRAM

AD9978A

INP_A

INM_A

INP_B

INM_B

CDS/
SHA

–3dB, 0dB, + 3dB, +6dB

–3dB, 0dB, + 3dB, +6dB

CDS/
SHA

6dB TO 42d B

VGA

6dB TO 42d B

VGA

INTERNAL CL OCKS

Precision

Timing

CORE

SYNC

GENERATOR

VDHD

Figure 1.

For more information about the AD9978A, contact Analog Devices, Inc., at [e-mail].

VREF

ADC

CLAMP

CLAMP

ADC

INTERNAL

REGISTERS

SL

SERIALIZER

SDATA

LVDS

SCK

DOUT0P
DOUT0N
DOUT1P
DOUT1N
TCLKP
TCLKN
DOUT2P
DOUT2N
DOUT3P
DOUT3N

CLICLK_OUT

07751-001

Rev. SpA

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. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] ©2008–2010 Analog Devices, Inc. All rights reserved.

AD9978A

NOTES

©2008–2010 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D07751F-0-1/10(SpA)

Rev. SpA | Page 2 of 2