XRD98L56 Datasheet, PDF (1/35 Pages) Exar Corporation – CCD Image Digitizers with CDS, PGA and 10-Bit A/D

XRD9855/9856
XRD98L55/98L56
CCD Image Digitizers with
CDS, PGA and 10-Bit A/D
FEATURES
l 10-Bit Resolution ADC
l 18 - 27MHz Maximum Sampling Rate
l Correlated Double Sampling (CDS)
l Programmable Gain from 6dB to 38dB (PGA)
l Digitally Controlled Analog Offset-Calibration
l CCD Black Level Offset Compensation at Frame
Rate
l CDS Clocks Sample Rising Edge or Falling Edge
l Single 5V or 3V Power Supply
l Low Power for Battery Applications:
XRD9855/56: 250/300m W @ V _DD = 5.0V
XRD98L55/L56: 120/150mW @ V_DD = 3.0V
l 50µA-Typ Current in Stand By Mode
l 3-State Digital Outputs
l ESD Protection to Over 2000V
APPLICATIONS
l Digital Video Camcorders
l Digital Still Cameras
l PC Video Teleconferencing
l Digital Copiers
l Infrared Image Digitizers
l CCD/CIS Imager Interface
l CCTV/Security Camera
l 2D Bar Code Readers
l Industrial Cameras
July 2001
GENERAL DESCRIPTION
The XRD9855/XRD9856 are complete CCD Image
Digitizers for digital cameras. The products include a
high bandwidth differential Correlated Double Sampler
(CDS), 8-bit digitally Programmable Gain Amplifier
(PGA), 10-bit Analog-to-Digital Converter (ADC) and
digital controlled black level auto-calibration circuitry.
The C orrelated D ouble Sam pler(C D S )subtracts the
C C D output signalblack levelfrom the video level.
C om m on m ode signalnoise and pow ersupply noise are
rejected by the differentialC D S inputstage.C D S inputs
are designed to be used either differentialor single-
ended.
The auto calibration circuitcom pensates forany inter-
naloffsetofthe X R D 9855/X R D 9856 as w ellas black
leveloffsetfrom the C C D .
The PGA is digitally controlled with 8-bit resolution on
a linear dB scale, resulting in a gain range of 6dB to
38dB with 0.125dB per LSB of the gain code.
The PGA and black level auto-calibration are controlled
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.
The XRD9855/XRD9856 has direct access to the PGA
output and ADC input through the pin TESTVIN.
The XRD9855/XRD9856 are packaged in 48-lead sur-
face mount TQFP to reduce space and weight, and
suitable for hand-held and portable applications.
ORDERING INFORMATION
Part No.
XRD9855AIV
XRD98L55AIV
XRD9856AIV
XRD98L56AIV
Package
48 Lead TQFP (7 x 7 x 1.4 mm)
48 Lead TQFP (7 x 7 x 1.4 mm)
48 Lead TQFP (7 x 7 x 1.4 mm)
48 Lead TQFP (7 x 7 x 1.4 mm)
Operating
Temperature Range Power Supply
-40°C to 85°C
5.0V
-40°C to 85°C
3.0V
-40°C to 85°C
5.0V
-40°C to 85°C
3.0V
Maximum
Sampling Rate
18 MSPS
18 MSPS
27 MSPS
27 MSPS
Rev. 1.01
EXAR Corporation, 48720 Kato Road, Fremont, CA 94538 • [phone] • FAX [phone] • www.exar.com