XRD98L59
CCD Image Digitizers with
CDS, PGA and 10-Bit A/D
January 2001-2
FEATURES
•
10-bit Resolution ADC
•
20MHz Sampling Rate
•
Programmable Gain: 6dB to 38dB PGA
(2x to 80x)
•
Improved Digitally Controlled Offset-Calibration
with Pixel Averager and Hot Pixel Clipper
•
DNS Filter Removes Black Level Digital Noise
•
Widest Black Level Calibration Range at
Maximum Gain
•
Manual Control of Offset DAC via Serial Port for
Use with High Speed Scanners
•
2ns/step Programmable Aperture Delay on SPIX
and SBLK
•
Single 2.7V to 3.6V Power Supply
•
Low Power for Battery Operation:120mW @ V
DD
=3V
•
•
•
•
5µA Typical Stand By Mode Current
Three-State Digital Outputs
2,000V ESD Protection
28-pin TSSOP Package
APPLICATIONS
•
Digital Still Cameras
•
•
•
•
•
•
•
Digital Camcorders
PC Video Cameras
CCTV/Security Cameras
Industrial/Medical Cameras
2D Bar Code Readers
High Speed Scanners
Digital Copiers
GENERAL DESCRIPTION
The XRD98L59 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), 8-bit digitally Program-
mable Gain Amplifier (PGA), 10-bit Analog-to-Digital
Converter (ADC) and improved digitally controlled
black level auto-calibration circuitry with pixel averager
hot pixel clipper, and a DNS filter.
The Correlated Double Sampler (CDS) subtracts the
CCD output signal black level from the video level.
Common mode signal and power supply noise are
rejected by the differential CDS input stage.
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 auto calibration circuit compensates for any inter-
nal offset of the XRD98L59 as well as black level offset
from the CCD.
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.
The XRD98L59 has direct access to the ADC input for
digitizing other analog signals. The XRD98L59 is
packaged in 28-lead surface mount TSSOP to reduce
space and weight, and is suitable for hand-held and
portable applications.
ORDERING INFORMATION
Operating
Temperature Range Power Supply
-40°C to 85°C
3.0V
Maximum
Sampling Rate
20 MSPS
Part No.
XRD98L59AIG
Package
28-Lead TSSOP
Rev. 2.00
EXAR
Corporation, 48720 Kato Road, Fremont, CA 94538
•
(510) 668-7000
•
FAX (510) 668-7017
•
www.exar.com
XRD98L59
PIN CONFIGURATION
OVDD
DB5
DB6
DB7
DB8
DB9
DVDD
DGND
SCLK
SDI
LOAD
PD
VRT
AVDD
!
"
#
$
%
&
'
!
"
&
%
$
#
"
!
'
&
%
$
#
OGND
DB4
DB3
DB2
DB1
DB0
SBLK
SPIX
CLAMP
CAL
VRB
AGND
REFin
CCDin
28-Lead TSSOP
PIN DESCRIPTION
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Symbol
OV
DD
DB5
DB6
DB7
DB8
DB9
DV
DD
DGND
SCLK
SDI
LOAD
PD
VRT
AV
DD
CCD
IN
REF
IN
AGND
VRB
CAL
CLAMP
SPIX
SBLK
DB0
DB1
DB2
DB3
DB4
OGND
Description
Digital Output Power Supply (< AV
DD
)
ADC Output
ADC Output
ADC Output
ADC Output
ADC Output, MSB
Digital Power Supply (Must = AV
DD
)
Digital Ground. Connect to AGND
Shift Clock. Latches SDI data on Serial Port
Serial Data Input. Serial Port
Data Load. Serial Port
Power Down, Active High
Top ADC Reference. Sets full scale of ADC
Analog V
DD
CDS inverting input. Connect through capacitor to CCD signal
Reference input (CDS non inverting input). Connect through capacitor
to CCD Ground
Analog Ground
Bottom ADC Reference. Sets zero for ADC.
Optical Black (OB) Clamp
CDS DC Restore Clamp
Sample Video Pixel (CDS Clock)
Sample Black Reference (CDS Clock)
ADC Output, LSB
ADC Output
ADC Output
ADC Output
ADC Output
Digital Output GND. Connect to AGND
Rev. 2.00
3
XRD98L59
XRD98L59
DC ELECTRICAL CHARACTERISTICS – XRD98L59
Unless otherwise specified: OV
DD
= DV
DD
= AV
DD
= 3.0V, Pixel Rate = 20MSPS, T
A
= 25°C
Symbol
Parameter
Min.
Typ.
Max.
Unit
Conditions
CDS Performance
CDSV
IN
V
DARK
r
ON
AV
MIN
AV
MAX
PGA n
Input Range
Maximum Dark Voltage Offset
CLAMP On Resistance
150
120
800 mV
PP
mV
Ω
Pixel (V
Black
- V
Video
), (See Figure 2)
At any gain. (See Figure 2)
PGA Parameters
Minimum Gain
Maximum Gain
Resolution
3.5
5
36
8
6.5
dB
dB
bits
Transfer function is linear steps in dB
(1LSB = 0.125dB)
ADC Parameters (Measured in ADCIN Test Mode), SDI = 0100 0000 0101 b
ADC n
f
s
DNL
EZS
EFS
V
IN
Resolution
Max Sample Rate
Differential Non-Linearity
Zero Scale Error
Full Scale Error
DC Input Range
GND
10
20
-1
+0.75
+25
1.5
AV
DD
1.5
bits
MSPS
LSB
mV
% FS
V
AV
IN
of the ADC can swing from AGND
to AV
DD
. Input range is limited by
the output swing of the PGA.
Measured relative to V
RB
∆V
REF
ADC Reference Voltage
2
V
V
RB
V
RT
Self Bias V
RB
Self Bias V
RT
(
(
V
RB
= AV
DD
10
V
RB
= AV
DD
1.30
)
)
0.2
0.3
0.4
V
2.0
2.3
2.6
V
Rev. 2.00
4
XRD98L59
DC ELECTRICAL CHARACTERISTICS - XRD98L59 (CONT'D)
Unless otherwise specified: OV
DD
= DV
DD
= AV
DD
= 3.0V, Pixel Rate = 20MSPS, T
A
= 25°C
Symbol
Parameter
Min.
Typ. Max.
Unit
Conditions
System Specifications
DNL
S
INL
SMIN
INL
SMAX
e
n
e
n
MAXAV
System DNL
System INL @ Minimum Gain
System INL @ Maximum Gain
Input Referred Noise @
Max Gain
-1
+0.75 1.5
2
2
0.2
LSB
LSB
LSB
mV
rms
mV
rms
No missing codes, monotonic
INL error is dominated by CDS/PGA
linearity
INL error is dominated by CDS/PGA
linearity
Gain Code = FFh
Gain Code =
00h
MINAV
Input Referred Noise @
Min Gain
0.7
Latency
Digital Inputs
V
IH
V
IL
I
L
C
IN
Digital Outputs
V
OH
V
OL
I
OZ
Pipeline Delay
4
cycles
Digital Input High Voltage
Digital Input Low Voltage
DC Leakage Current
Input Capacitance
2.1
0.5
5
5
V
V
µA
pF
V
IN
= GND or V
DD
Digital Output High Voltage
Digital Output Low Voltage
High–Z Leakage
OV
DD
-0.5
V
0.5
V
µA
While sourcing 2mA
While sinking 2mA
OE = 0 or PD = 1
Output = OGND or ODV
DD
-10
10
Rev. 2.00
5
Talking
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