XRD9836 Datasheet, PDF (1/32 Pages) Exar Corporation – 16-BIT PIXEL GAIN AFE

xr
XRD9836
JUNE 2003
16-BIT PIXEL GAIN AFE
REV. 1.0.0
GENERAL DESCRIPTION
The XRD9836 is a precision 16-bit analog front-end
(AFE) for use in 3-channel/1-channel CCD/CIS docu-
ment imaging applications. Pixel-by-pixel gain and
offset for each of the 3 channels are controlled using
a time multiplexed parallel input. Offset and Gain are
sequentially supplied for red, green, and blue. The
outputs from each of the three channels are transmit-
ted time multiplexed with the high order byte first fol-
lowed by the low order byte for red, blue and green.
FEATURES
• 16-bit resolution ADC, 30MHz Sampling Rate
• 10-bit accurate linear programmable gain range select-
able as either 2-to-20 V/V or 1-to-10 V/V per channel
• Fully-differential input pins and internal path
• Sampling rates from 1.0 MSPS to 10.0 MSPS per chan-
nel for 3 -Channel mode and up to 15.0 MSPS in single
channel mode.
• Pixel-by-Pixel Offset and Gain control through a parallel
interface running at a maximum 60 Mbyte/sec. data rate
• A microprocessor serial port to control various modes of
operation
• Fixed Gain/Offset Mode (FGOM) or Pixel by Pixel Gain/
Offset Mode (PPGOM)
• Alternate Pixel Offset Adjust Mode (APOAM)
• Low Power CMOS=280mW (typ. @ 3V); Power-Down
Mode=1mW (typ. @ 3V with static clocks)
• Single Power Supply (3.0 to 3.6 Volts) with Max CCD
input signal of 1V and reset pulse up to 0.5V
• High ESD Protection: 2000 Volts Minimum
APPLICATIONS
• Scanners, MFP’s
FIGURE 1. BLOCK DIAGRAM
OFFSET/GAIN
INPUT ₁₀
ADCLK
IE
GRN+
RED-
RED+
GRN-
BLUE+
BLUE-
CAPP
CAPN
CMREF
REXT
ANALOG INPUTS
BIAS
RED GAIN
REGISTER
RED OFFSET
REGISTER
Red Gain
10
10
Red Offset
RED
CDS &
PGA
GREEN GAIN Green Gain
REGISTER
10
GREEN OFFSET 10
REGISTER _{Green Offset}
Green
CDS &
PGA
BLUE GAIN
REGISTER
BLUE OFFSET
REGISTER
Blue Gain
10
10
Blue Offset
BLUE
CDS &
PGA
XRD9836
M
U
D
16-BIT 16
E
M
X
30MHz
ADC
U
X
RED HIGH ORDER
ADC OUT
RED LOW ORDER
ADC OUT
GREEN HIGH ORDER
ADC OUT
GREEN LOW ORDER
ADC OUT
BLUE HIGH ORDER
ADC OUT
BLUE LOW ORDER
ADC OUT
SERIAL PORT
SCLK
SDATA
LOAD
TIMING
VSAMP
BSAMP
LCLMP
POWER
33
Avdd
Agnd
Dvdd
22
Ognd
Ovdd
Dgnd
8 ADC
OUT
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com