CCD Image Digitizers with
CDS, PGA and 12-Bit A/D
June 2003
XRD98L63
FEATURES
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12-bit Resolution ADC, 30MHz Sampling Rate
10-bit Programmable Gain: 6dB to 36dB PGA
Pixel-by-pixel gain switching
Digitally Controlled Black Level Calibration with
Pixel Averager and Hot Pixel Clipper
DNS Filter Removes Black Level Digital Noise
Programmable Black Level, up to code 255
Black Level Calibration Range: 300 mV
Programmable Aperture Delays
1.0 ns/step for SBLK & SPIX
0.5 ns/step for ADCLK
Manual Control of Offset DACs via Serial Port
for use with High-speed Scanners
Single 2.7V to 3.6V Power Supply
Optimize power with external resistor to 100mW
Low Power for Battery Operation
100µA Stand-by Mode Current
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Three-state Digital Outputs
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3,000V ESD Protection
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48-pin TQFP Package
APPLICATIONS
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Mega pixel Digital Still Cameras
Digital Camcorders
3 CCD Professional/Broadcast Camera
Line Scan Cameras
PC Video Cameras
CCTV/Security Cameras
Industrial/Medical Cameras
2D Bar Code Readers
High Speed Scanners
Digital Copiers
GENERAL DESCRIPTION
The XRD98L63 is a complete, low power CCD Image
Digitizer for digital motion and still cameras. The
product includes a high bandwidth differential Corre-
lated Double Sampler (CDS), 10-bit Programmable
Gain Amplifier (PGA) with pixel rate gain switching, 12-
bit Analog-to-Digital Converter (ADC) and improved
digitally controlled black level auto-calibration circuitry
with programmable pixel averaging, hot pixel clipping,
and a Digital Noise Suppression (DNS) filter.
The Correlated Double Sampler (CDS) subtracts the
CCD output signal black level from the video level.
Common mode and power supply noise are rejected by
the differential CDS input stage.
The PGA is digitally controlled with 10-bit resolution on
a dB scale, resulting in a gain range of 6dB to 36dB with
0.047dB per LSB of the gain code. The PGA can be
programmed to switch gain every pixel, in a user
defined pattern of up to 4 different gains. Our propri-
etary control logic allows a camera system to set the
desired gain ratios for color balance. The system gain
can then be changed by writing to a single register,
and the color balance will be maintained.
The black level auto-calibration circuit averages the
results of the Optical Black pixels to compensate for
any internal offset of the XRD98L63 as well as black
level offset from the CCD. The calibration logic uses
proprietary digital filters to eliminate line-to-line offset
noise and noise due to hot pixels in the Optical Black
areas.
The PGA and black level auto-calibration are con-
trolled through a simple 3-wire serial interface. The
timing circuitry is designed to enable users to select a
wide variety of available CCD and image sensors for
their applications. Readback of the serial data regis-
ters is available from the digital output bus.
The XRD98L63 is packaged in 48-lead TQFP to reduce
space and weight, and is suitable for hand-held and
portable applications.
ORDERING INFORMATION
Part No.
XRD98L63AIV
Package
48-Pin TQFP
Temperature Range
-40°C to 85°C
Operating
Power Supply
2.7V to 3.6V
Maximum
Sampling Rate
30 MSPS
Rev.1.01
EXAR
Corporation, 48720 Kato Road, Fremont, CA 94538
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(510) 668-7000
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FAX (510) 668-7017
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www.exar.com
EXAR [ EXAR CORPORATION ]
