Samsung Electronics
5-1
5 . Circuit Descript ion
5-1 Logic Section
5-1-1 Power Supply
With the battery installed on the phone and by
pressing the END/ key, the VBATT and
ON_SW signals will be connected. This will turn
on U123 DC_DC convertor.
This in turn will be supplied to PIN3, PIN4 of
regulators U124, PIN6 of regulators U122, thus
releasing them from the shut-down state to output
regulated 3.3V. ( The VBATT applied to ON-SW
will turn on Q103(DTC144EE) resalting in the
signal ON-SW-SENSE to change start the from
High to Low.)
The MSM recognizes this signal and sends out
PS_HOLD (logical HIGH) to turn on Q102 even
after the PWR key is released.
The power from U124 is used in the digital part of
MSM and BBA. The power from U122 is used in
analog part of BBA.
5-1-2 Logic Part
The logic part consists of internal CPU of MSM,
RAM, ROM and EEPROM. The MSM receives
TCXO and CHIPX8 clock signals from the BBA
and controls the phone during the operation. The
major components are as follows:
¶U
CPU
: INTEL 80186 core (inside the MSM)
¶U
FLASH ROM : U129 - 8 Mbit FLASH MEMORY
¶U
SRAM
: U127 - 2 Mbit STATIC RAM
¶U
FLASH ROM : U130 - 1 Mbit FLASH MEMORY
¶U
EEPROM : U102 - 128 Kbit SERIAL EEPROM
CPU
INTEL 80186 CMOS type 16-bit microprocessor is
used for the main processing. The CPU controls all
the circuitry. For the CPU clock, 27MHz resonator
is used.
FLASH ROM
One 8 MBIT FROM is used to store the terminal's
program. Using the down-loading program, the
program can be changed even after the terminal is
fully assembled.
SRAM
One 2 MBIT SRAMs is used to store the internal
flag information, call processing data, and timer
data.
EEPROM
One 128 KBIT EEPROM is used to store ESN,
NAM, power level, volume level, and telephone
number.
KEYPAD
For key recognition, key matrix is setup using
SCAN0-6 of STORE signals and KEY0-3 of input
ports of MSM. Ten LEDs and backlight circuitry
are included in the keypad for easy operation in
the dark.
LCD MODULE
LCD module contains a controller which will
display the information onto the LCD by 8-bit data
from the MSM. It also consists a DC-DC converter
to supply -3.5V for fine view angle and LCD
reflector to improve the display efficiency.
Summary of Contents for SCH-470
Page 2: ... à Samsung Electronics Co Ltd APR 1998 Printed in Korea Code No GH68 60687A ...
Page 6: ...2 2 Samsung Electronics ...
Page 12: ...NAM Programming 3 6 Samsung Electronics ...
Page 24: ...Circuit Description 5 10 Samsung Electronics ...
Page 26: ...Exploded View and its Parts List 6 2 Samsung Electronics 6 1 Fixed Phone Exploded View ...
Page 30: ...6 6 Samsung Electronics Exploded View and its Parts List ...
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Page 43: ...Samsung Electronics 8 1 8 Troubleshoot ing 8 1 Logic Section 8 1 1 No Power ...
Page 45: ...Samsung Electronics 8 3 Troubleshooting 8 1 3 Abnormal Backlight Operation ...
Page 46: ...Troubleshooting 8 4 Samsung Electronics 8 1 4 Abnormal Key Data Input ...
Page 47: ...Samsung Electronics 8 5 Troubleshooting 8 1 5 Abnormal Keytone ...
Page 48: ...Troubleshooting 8 6 Samsung Electronics 8 1 6 Abnormal Alert Tone ...
Page 49: ...Samsung Electronics 8 7 Troubleshooting 8 2 RF Section 8 2 1 RF Secton Troubleshooting ...
Page 50: ...Troubleshooting 8 8 Samsung Electronics 8 2 2 Receiver Part ...
Page 51: ...Samsung Electronics 8 9 Troubleshooting 8 2 3 Transmitter Part ...
Page 52: ...Troubleshooting 8 4 Desk Top charger 8 4 1 Check 1 8 10 Samsung Electronics ...
Page 53: ...Troubleshooting Samsung Electronics 8 11 ...
Page 54: ...8 4 2 Check 2 Troubleshooting 8 12 Samsung Electronics ...
Page 55: ...8 4 3 Check 3 Troubleshooting Samsung Electronics 8 13 ...
Page 56: ...Troubleshooting 8 14 Samsung Electronics ...
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