Circuit Description; Circuit Description Of Control Pwb; Chapter 5. Circuit Description - Sharp AM-900 Service Manual

AM-900U
FAX CHAPTER 5. E Market Service Manual Service Manual AM-900U

CIRCUIT DESCRIPTION

[1] Circuit description
1. General description
The compact design of the control PWB is obtained by using MFP
ASIC OA-2000 in the main control section and high density printing of
surface mounting parts. Each PWB is independent according to its
function as shown in Fig. 1.
2. PWB configuration
FAN
AC CORD
POWER
HEATER
SUPPLY
LAMP
PWB
LIU
LINE CABLE
PWB
OPERATION
PANEL PWB
2.1. Control PWB
The control PWB controls peripheral PWBs, mechanical parts, trans-
mission, and performs overall control of the unit.
2.2. LIU PWB
This PWB controls connection of the telephone line to the unit.
2.3. Power supply PWB
This PWB provides voltages of +3.3V, +5V and +24V to the another
PWB.
2.4. Panel PWB
The panel PWB allows input of the operation keys.
2.5. High voltage PWB
This PWB provides the high voltage to printer process units.
2.6. LCD PWB
This PWB controls the LCD display.
HIGH VOLTAGE PWB
OPTICAL UNIT (LSU)
ROLLER SENSOR
MAIN MOTOR
TONER C/T SENSOR
CONTROL
PWB
FUSING UNIT
THERMISTOR
SPEAKER
PICKUP MOTOR
CIS SCANNER
MOTOR
LCD
Fig. 1

[2] Circuit description of control PWB

1. General description
The control PWB is composed of the following blocks..
1.1. Main control block
1) Controller block
2) Memory block
3) Modem block
4) Scanner I/F block
5) Panel I/F block
1.2. Printer control block
1.3. Power section
2. Description of each block
2.1. Main control block
Main control block consisting of CPU OA-2000 with 32bit microproces-
sor core, SDRAM (128Mbit), FLASH (16Mbit), FAX MODEM, etc., con-
trols scanning, images processing, FAX communication, user
interface, USB interface etc., that is all except for printer controlling.
2.1.1 Controller block
1) OA-2000 (IC1): pin-208 QFP (Main CPU)
This is a microcomputer with 32bit microprocessor (ARC) core, which
periphery functions are integrated into.
This device is equipped with the following function. The clock inputs
24MHz from outside and operates at 4-times frequency (96MHz) inter-
nally.
Feature
• SDRAM Controller
Addressing, Control and Refresh to SDRAM (IC4)
• USB 2.0 Client I/F (High Speed & Full Speed)
Connection for PC
• General Purpose I/O port
Controlling Panel, LIU, Motor driver, etc.
Inputting of each sensor and status signals
• Contact Image Sensor I/F and Analog Front End
Processing of SCAN video signal and its A/D conversion.
• Hardware Image Processing Accelerators
• JBIG & JPEG Hardware Image Compression and Decompression
• Serial communication I/F
Communicating with Printer CPU (IC21)
• Peripheral Bus I/F
FAX MODEM (IC18) and KEY & STATUS signal buffer (IC10) is
connected via Peripheral Bus.
• Pulse Width Modulators
This generates key input sound, alarm sound and ringer sound.
• Real Time Clock Generator
It is oscillated with quartz oscillator of 32.768kHz and the clock is
provided.
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