SANYO LC821031 Datasheet
Overview
The LC821031 converts analog video signals from CCD
and contact sensors to high-quality binary image data. It
includes both an 8-bit A/D converter and a 6-bit D/A
converter for setting the reference potential and creates
high-quality multi-valued data using a gamma conversion
technique that supports arbitrary gamma curves. It also
provides both black and white all-pixel distortion
correction and multi-valued resolution conversion. It then
applies two-dimensional filtering to this multi-valued data
to separate the document image into text, photograph, and
halftone areas. After converting the image to a binary
image using an error diffusion technique that acquires
high-quality images, it applies reduction in both the
primary and secondary scan directions. Since the
LC821031 limits the number of pixels processed per line
to 3072 pixels, it needs no external memory to implement
this processing. Thus the LC821031 implements the image
processing used by facsimile, copier, and OCR products.
Features
• Number of pixels processed: 3072 pixels/line
• Processing speed: 250 ns/pixel, maximum (When
CLKIN = 32 MHz)
• 8-bit A/D converter (Includes a sensor signal timing
adjustment function.)
• 6-bit D/A converter for setting the A/D converter
reference potential
• Sensor drive circuit (Supports most CCD and CIS
devices.)
• Digital clamp (single-point clamping and even/odd
clamping)
• Distortion correction (white correction: all-pixel
correction, black correction: all-pixel correction)
• Gamma correction (Supports user-defined curves: 8-bit
data)
• Image area separation
• Simple binary coding (fixed threshold and density
adaptive threshold)
• Halftone processing: error diffusion method (64 levels)
• Multi-value resolution conversion (Conversion ratios of
1:2, 2:3, 3:2, and 2:1)
• Binary image reduction (Main scan line direction:
decimation, fine black line retention, fine white line
retention; secondary scan line direction: decimation, fine
line retention)
• Fabricated in a CMOS process for single 5-V powersupply and low power.
Package Dimensions
unit: mm
3159-QFP64E
CMOS LSI
22898HA (OT) No. 5735-1/5
Preliminaly
SANYO: QIP64E
[LC821031]
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-0005 JAPAN
Image-Processing IC for Facsimile, Copier,
and OCR Products
LC821031
Ordering number : EN*5735
Parameter Symbol Conditions Ratings Unit
Maximum supply voltage V
DD
max –0.3 to +7.0 V
Input and output voltage V
I
, V
O
–0.3 to VDD+0.3 V
Allowable power dissipation Pd max Ta ≤ 70°C 350 mW
Operating temperature Topr –30 to +70 °C
Storage temperature Tstg –55 to +125 °C
Soldering conditions
Hand soldering: 3 seconds 350 °C
Reflow soldering: 10 seconds 235 °C
Specifications
Absolute Maximum Ratings at Ta = 25°C, GND = 0 V
No. 5735-2/5
LC821031
Parameter Symbol Conditions
Ratings
Unit
min typ max
Supply voltage V
DD
4.5 5.5 V
Input voltage V
IN
0 V
DD
V
Allowable Operating Ranges at Ta = –30 to +70°C, GND = 0 V
Parameter Symbol Conditions
Ratings
Unit
min typ max
Input high-level voltage V
IH
2.2 V
Input low-level voltage V
IL
0.8 V
Input leakage current I
IH, LVIN
= VDD, V
SS
–10 +10 µA
Output high-level voltage V
OHIOH
= –3 mA 2.4 V
Output low-level voltage V
OLIOL
= 3 mA 0.4 V
Output leakage current I
L
When high-impedance –10 +10 µA
Current drain I
DD
CLKIN = 32 MHz 40 70 mA
DC Characteristics at Ta = –30 to +70°C, GND = 0 V, VDD= 4.5 to 5.5 V
Parameter Symbol Conditions
Ratings
Unit
min typ max
[D/A Converter]
Resolution 6 bit
Internal resistance 4.8 kΩ
[A/D Converter] ATAPL potential: 0.8 V, ATAPH potential: 4.2 V
Resolution 8 bit
Linearity error ±1 LSB
Differential linearity error ±1 LSB
Internal resistance 330 Ω
Analog Characteristics
Block Diagram
Registers
Controller
Analog
block
Distortion
correction
Filters
Image area
separation
Multi-valued
resolution
conversion
Gamma
correction
Binary
correction
Sensor
motor drive
Output
control
Binary
image
reduction
Halftone
2-kilobit
SRAM
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