Samsung SCH-1900 Service Manual

C D M A P O R TA B L E

Manual

PCS T E L E P H O N E

SCH-1900

S E RVICE

CDMA PORTABLE PCS TELEPHONE

CONTENTS

1. Specification

2. Installation

3. NAM Programming

4. Circuit Description

5. Test Procedure

6. Troubleshooting

7. Exploded Views and Parts List

8. PCB Diagrams

9. Electrical Parts List

10. Block & Circuit Diagrams

Samsung Electronics Co.,Ltd.

GH68-60620A

Printed in Korea.

1. Specification

1-1 General

Frequency Range

Transmitter : 1850 ° ≠1910 MHz
Receiver : 1930 ° ≠1990 MHz

Channel Bandwidth : 1.23 MHz

Channel Spacing : 50 KHz

Number of Channels : 1200

Duplex Separation : 80 MHz

Type of Emission : G7 W

Input/Output Impedance : 50 ohms

Intermediate Frequency

Transmitter : 130.38 MHz
Receiver : 210.38 MHz

Local Frequency

Transmitter : 1st (FTX-130.38), 2nd (260.76 MHz)
Receiver : 1st (FRX-210.38), 2nd (420.76 MHz)

TCXO Frequency : 19.68 MHz

Frequency Stability : (FRX - 80 MHz) °æ 150 Hz

Operating Temperature : -30 °… ° ≠+60 °…

Supply Voltage : +4.8 V

Current Consumption (Average)

Standby : 150 mA (Non-slot mode)
Talk : 400 mA (at +10 dBm)

Size and Weight

Including Standard Battery : 114(H)°ø49.8(W)°ø10.5(D), 118.67 g
Including Extended Battery : 114(H)°ø49.8(W)°ø20.5(D), 161.86 g

Samsung Electronics 1-1

Specification

1-2 Transmitter

Waveform Quality : 0.944 or more

Open Loop Power Control Range

-25 dBm : -60.5 dBm ° ≠-41.5 dBm

-65 dBm : -20.5 dBm ° ≠-1.5 dBm

-104dBm : +15.0 dBm ° ≠+30.0 dBm

Minimum Tx Power Control : -50 dBm below

Closed Loop Power Control Range : °æ24 dB

Maximum RF Output Power : 200 mW (+23 dBm)

Occupied Bandwidth : 1.23 MHz

Conducted Spurious Emissions @1.25MHz : -42 dBc/30KHz

1-3 Receiver

Rx Sensitivity and Dynamic Range : -104 dBm, FER=0.5% or less

(Rate Set 1) : -25 dBm, FER=0.5% or less

Conducted Spurious Emission

1930 ° ≠1990 MHz : <-81 dBm
1850 ° ≠1910 MHz : <-61 dBm
All Other Frequencies : <-47 dBm

Single Tone Desensitization : lower than 1%

Rx power=-101 dBm
Tone power=-30 dBm
Tone offset from carrier=°æ1.25 MHz

Intermodulation Spurious Response Attenuation : lower than 1%

Rx power=-101 dBm
Tone power 1=-43 dBm
Tone power 2=-43 dBm
Tone 1 offset from carrier=°æ1.25 MHz
Tone 2 offset from carrier=°æ2.05 MHz

1-2 Samsung Electronics

2. Installation

2-1 Installing a Battery Pack

1. To attach the battery pack after charging, align
it with the phone about 1cm (1/2") away from
its place so that the two arrows on the phone
are seen, the battery charge contacts pointing
downwards.

2. Slide the battery pack upwards until it clicks
firmly into position. The phone is now ready
to be turned on.

2-2 For Desk Top Use

1. Choose a proper location to install the charger
for desk top use.

2. Plug the power cord of the charger into an
appropriate wall socket. When the power cord
is connected correctly, the lamps turn on
briefly.

3. To remove the battery pack, release it by
pressing the button on the rear of the phone.

4. Slide the battery pack downwards about 1cm
(1/2") and lift it away from the phone.

Press this button to release
the battery pack

3. To charge the battery pack, insert the battery
pack into the rear slot of the charger. The lamp
marked BAT on the front panel of the charger
lights up red.

4. If you do not wish to use the phone while
charging the battery, insert the phone with the
battery pack attached into the front slot of the
charger. The lamp marked PHONE on the
front panel of the charger lights up red.

Figure 2-1 Charging The Phone and Battery

Samsung Electronics 2-1

Installation

2-3 For Mobile Mount

2-3-1 Antenna

1. Choose a proper location to install the
antenna.
¶UThe center of the roof top provides the best

performance.

¶UThe edge of the rear trunk also provides a

good performance. However, the antenna
should be higher than the roof of the car.

¶UIn case of on-glass antenna, you should

align the antenna base with the round plate
to connect the cables correctly.

2. Mount the antenna vertically, connect the
antenna cable.

3. Tighten the antenna nut fully.

2-3-2 Cradle

1. Choose a location where it is easy to reach and
does not interfere with the driver's safe
operation of the car.

2. Separate the two halves of the clamshell by
removing the two large slotted screws. See the
figure 2-2.

3. Drill holes and mount the lower half of the
clamshell by using the screws.

4. Place the cradle onto the remaining half of the
clamshell and assemble them by using the
screws.

5. Reassemble the two halves of the clamshell
together. Adjust the mounting angle and
tighten the two slotted screws.

Figure 2-2 Cradle Installation

2-2 Samsung Electronics

Installation

2-3-3 Hands-Free Box

1. Drill holes in a proper location for the hands­free box, attach the mounting bracket by using
the screws. See the figure 2-3.

2. Install the hands-free box into the bracket.

2-3-4 Hands-Free Microphone

1. It is recommended to install the microphone
where it is 30-45 cm (12-18") away from the
driver. Choose the location where is least
susceptible to interference caused by external
noise sources, ie, adjacent windows, radio
speakers, etc. Normal place is the sun visor.

2. Once the microphone has been correctly
positioned, connect the microphone wire to
the MIC jack on the hands-free box.

Figure 2-3 Hands-Free Box Installation

Samsung Electronics 2-3

Installation

2-3-5 Cables

1. Connect the cradle and the hands-free box
with the data cable. See the figure 2-4.

2. Connect the antenna cable to the RF jack of the

cradle.

3. Connect one end of the power cable to the

battery or ignition terminal. Connect the red
wire to the battery (+) terminal, black wire to
the vehicle chassis. Then connect the battery (-)
terminal to the vehicle chassis.

4. Connect the other end of the power cable to

the PWR jack of the hands-free box.

Notes:
¶UIt is recommended to connect the power cable

directly to the battery to avoid power noise.

¶UMake sure the connection between the battery -

terminal and the vehicle chassis is made
correctly.

¶UMake sure the fuse having a proper capacity is

used on the power cable.

¶UMake sure the cables do not pass over any sharp

metal edge that may damage it.

Figure 2-4 Cable Connections

2-4 Samsung Electronics

3. NAM Programming

NAM features can be programmed as follows:
Notes:

-If you enter the NAM program mode, each item shows the currently stored data. Go to the next item by

pressing OK.

-You can modify the data by entering a new data.

-If you enter a wrong digit, press CLR to delete the last digit. Press and hold CLR to delete all digits.

-To scroll items backwards or forwards, press the VOLUME button on the left side of the phone.

3-1 General Setup

LCD Display Key in Function

MENU, 5, 0 -selects NAM programming

Enter Lock

??????

SVC Menu°Ë°È
1:PCS Phone#
2:General

ESN

B0000000

CAI version

VOC13K/8K
SO_VOICE_13K

SCM

00001010

Lock Code

0000

Slot Mode

No

6-digit code -Enter random 6-digit code (MSL)

2 -choose 'GENERAL.'

Volume °„ -Electronic Serial Number of the phone is displayed

Volume °„ -Common Air Interface version is displayed

1

°Ëor°È -Select vocoder service option

OK -stores it
Volume °„ -Station Class Mark displays the power class,

transmission, slotted class, dual mode.

Lock code, current status is displayed

4-digit code -to change, enter new code.
OK -stores it.

Slot mode. 'Yes' indicates the slot mode.

°Ëor°È -changes the status.
OK -stores it.

Slot Index

2

Samsung Electronics 3-1

0 - 7 -to change, enter new one.
OK -stores it.

Slot mode index. The higher, the longer sleeping time.

NAM Programming

3-2 Setting Up NAM

LCD Display Key in Function

SVC Menu°Ë°È
1:PCS Phone #
2:General

Volume °„ -NAM Programming Menu is displayed

SVC Menu°Ë°È
3:NAM

IMSI_MCC

310

IMSI_MNC

00

CDMA ACCOLC

CDMA HomeSID

Yes

CDMA fSID

Yes

CDMA fNID

Yes

3 -choose 'Setup NAM'

number IMSI Mobile Country Code, current code is displayed.
OK -to change, enter new one.

-stores it.

number IMSI Mobile Network Code, current code is displayed.
OK -to change, enter new one.

-stores it.

CDMA Access Over load Class, current status is displayed.

0

class number -to change, enter new one.
OK -stores it.

CDMA Home system ID, current status is displayed.

°Ëor°È -changes the status.
OK -stores it.

CDMA foreign SID, current status is displayed.

°Ëor°È -changes the status.
OK -stores it.

CDMA foreign NID, current status is displayed.

°Ëor°È -changes the system.
OK -stores it.

SID

4120

NID

65535

3-2 Samsung Electronics

number -to change, enter new one.
OK -stores it.

number -to change, enter new one.
OK -stores it.

first SID written in the list, current status is displayed.

first NID written in the list, current status is displayed.

4. Circuit Description

4-1 Logic Section

4-1-1 Power Supply

With the battery installed on the phone and by

pressing the PWR key, the VBATT and ON_SW
signals will be connected. This will turn on
Q108(2SC4081). This in turn will be supplied to

pin 6 of regulators U110 and U111, thus releasing

them from the shut-down state to output
regulated 3.3V. And then the pin 8 of (U110) stays

High.

The VBATT applied to ON_SW turns on
Q113(DTC144) and will result in the signal
ON_SW_SENSE to change state from HIGH to
LOW. The MSM recognizes this signal and sends
out PS_HOLD(logical HIGH) to turn on
Q108 even after the PWR key is released.

The power from U110 is used in the digital part of
MSM and BBA. The power from U111 is used in
the analog part of BBA.

4-1-2 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. The major components are
as follows:

¶UCPU : INTEL 80186 core
¶UFROM : U112 (MBM29LV800T)-8MBIT

FLASH ROM

¶USRAM : U113(KM68V2000BLTI)-2MBIT

STATIC RAM

¶UEEPROM : U109(24LC65-1/SM)-64KBIT

SERIAL EEPROM

CPU

INTEL 80186 CMOS type 16-bit microprocessor is
used and CPU controls all the circuitry. For the
CPU clock, 27MHz is used.

FLASH ROM

One 8Mbit 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 2Mbit SRAM is used to store the internal flag
information, call processing data, and time data.

EEPROM

One 64Kbit EEPROM is used to store ESN, NAM,
power level, volume level, and telephone number.

KEY-PAD

For key recognition, key matrix is setup using
SCAN0-6 of STROBE signals and KEY0-2 of input
ports of MSM. Six 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 -3.3V for fine view angle and LCD
reflector to improve the display efficiency.

Samsung Electronics 4-1

Circuit Description

4-1-3 Base Band

MOBILE SYSTEM MODEM (MSM)

The MSM equipped with the INTEL 80186 CPU
core is an important component of the CDMA
cellular phone. The MSM comes in a 176 pins
TQFP package. The interface block diagram is
shown on page4-3.

MICROPROCESSOR INTERFACE

The interface circuitry consists of reset circuit,
address bus (A0-A19), data bus (AD0-AD15), and
memory controls (ALE,DT-R,HWR/,LWR/,
RAM_CS/,ROM_CS).

INPUT CLOCK

°§CPU clock : 27 MHz
°§TXCO/4 (pin34) : 4.92 MHz. This clock signal

from the BBA is the reference clock for the MSM
except in CDMA mode.

°§CHIPX8 : 9.8304 MHz.The reference clock used

during the CDMA mode.

ADC Interface

ADC_CLK (pin3), ADC_ENABLE (pin1) and
ADC_DATA (pin2) are required to control the
internal ADC in the BBA.

Data Port Interface

Includes the UART. Also, supports Diagnostic
Monitor (DM) and HP equipment Interface.

CODEC Interface

The MSM outputs 2.048MHz PCM_CLK (pin19)
and 8KHz CODEC_SYNC (pin16,20) to the
CODEC (U102). The voice PCM data from the
MSM (U101)PCM_DIN (pin135) is compressed
into 13KHz by PureVoice algorithm in the CDMA
mode.

RF Interface

BBA INTERFACE

CDMA,Data Interface

°§TX_IQDATA0-7 (pin24-32) : TX data bus used

during both CDMA.

°§C_RX_IDATA0-3 (pins16-20) and

C_RX_QDATA0-3(pins 12-15) : RX data bus
used during CDMA mode.

Clock

°§TX_CLK(pin 22), TX_CLK/(pin23) : Digital to

Analog Converter(DAC) reference clock used in
TX mode.

°§CHIPX8 : ADC reference clock used in CDMA

RX mode.

TX : TX_AGC_ADJ (pin35) port is used to control
the TX power level and PA_ON (pin44) signal is
used to control the power amplifier.

RX : AGC_REF (pin36) port is used to control the
RX gain and TRK_LO_ADJ (pin45) is used to
compensate the TCXO clock.

General Purpose I/O Register Pins

Input/output ports to control external devices.

Power Down Control

When the IDLE/signal turns LOW, only the TX
sections will be disabled.If both the IDLE/ and
SLEEP/ are changed to LOW, all the pins except
for the TXCO are disabled.

4-2 Samsung Electronics

Circuit Description

Figure 4-1 Baseband Block Diagram

4-1-4 Audio Section

TX AUDIO PATH

The voice signal output from microphone is
filtered and amplified by the internal OP-AMP
and is converted to PCM data by the
CODEC(U102). This signal is then applied to the
MSM(U101)'s internal vocoder.

RX AUDIO PATH

The PCM data from the MSM are converted to
audio signal by DAC of CODEC(U102),is then
amplified by the speaker amplifer(U105) to be sent
to the speaker unit.

VOLUME ADJUST

Volume can be adjusted up to 8 steps for the user
to obtain a proper loudness of received signal.

4-1-5 Buzzer Driving Circuitry

Buzzer generates alert tone. When the buzzer
receives the timer signal from the MSM, it
generates alert tone. The buzzer level is adjusted
by the alert signal's period generated from the
MSM timer.

4-1-6 Key Tone Generator

Ring signal (pin49) from MSM(U101) is passed
through LPF consisting of R180, C119, R124, and
C120, amplified at the speaker amp(U105) and
come out to speaker.

Samsung Electronics 4-3

Circuit Description

4-2 Receiver Section

LOW NOISE AMPLIFIER (LNA)

The low noise amplifier featuring 1.6dB Noise
Figure and 19dB gain amplifies a weak signal
received from the base station to obtain the
optimum signal level.

DOWN CONVERTER (MIXER)

First local signal is applied to this down converter.
The down converter transfers the signal amplified
at the LNA into 210.38 MHz IF signal. 210.38MHz
IF signal is made by subtracting 1960°æ30MHz RF

signal from 1749.62°æ30MHz first local signal. The
LNA is Q303 and down converter is U302.

IF AMP

The IF amp (Q310) amplifies the output signal of
the down converter (U302).

RF IF AUTOMATIC GAIN CONTROLLER
(AGC) AMP

210.38 MHz IF signal is applied to IF AGC
amp,the AGC output level is applied to BBA (Base
Band Asic). The AGC amp (U303) keeps the signal
at a constant level by controlling the gain.
Dynamic range is 90dB, up gain +45dB, and down
gain -45dB.

RF BAND PASS FILTER (BPF)

The RF BPF(F302) accepts only a specific
frequency (1960°æ30MHz) from the signal

received from the mobile station. The bandwidth
is 60MHz.

BUFFER

Buffer (Q311) amplifies the signal from the VCO
(U305) to be applied to the local input of the down
converter (U302) when a phase is locked between
U304 and U305.

The VCO (U305) generates the signal having
1750MHz center frequency and °æ30MHz

deviation with the voltage control. PLL IC(U304)
controls this signal.

PHASE LOCKED LOOP (PLL)

Input reference frequency is generated at
VCTCXO (U306) and the local signal is generated
at VCO. PLL compares the two signals and allows
the VCO controlled by voltage to generate the
desired signal with pre-programmed counter.

VOLTAGE CONTROLLED TEMPERATURE
COMPENSATED CRYSTAL OSCILLATOR

It provides 19.68MHz reference frequency to PLL
(U304) and BBA (U401). A correct frequency
tuning is made by the voltage control.

DUPLEXER

Duplexer (F301) controls to transmit through the
antenna only the signals within acceptable Tx
frequency range (1880°æ30MHz) and to receive

through the antenna only the signals within
acceptable Rx frequency range (1960°æ30MHz). It

also matches LNA(Q303) input in receiving part
and PA output in transmitter part with the
antenna.

IF SAW BAND PASS FILTER FOR CDMA

IF SAW BPF (F303) is used for CDMA system
having 1.23 MHz wide band and °æ630kHz band

width. The filter also eliminates the image product
generated at the mixer.

4-4 Samsung Electronics

4-3 Transmitter Section

Circuit Description

POWER AMP MMIC

Power Amp MMIC (U407) amplifies signal to be
sent out to the base station through the antenna.

DRIVER AMP

The driver amp (Q413) allows the input signal to
the power amp MMIC(U407) to be within a
specified level.

UP CONVERTER (MIXER)

The up-converter (U405) receives the first local
signal to generate 1880°æ30MHz from the signal

controlled by TX AGC amp (U404). 1880°æ30MHz
signal comes out of the mixer output by adding

130.38MHz IF signal to 1749.62°æ30MHz first local
signal. The driver amp's reference number is Q413

and up converter's reference number is U405.

IF AUTOMATIC GAIN CONTROLLER AMP

ANTENNA

ANT1 allows signals to send and to receive to
from the base station.

RF BAND PASS FILTER (BPF)

The RF BPFS (F402, F403) accept only a specific
frequency (1880°æ30MHz) to send it out to power

amp MMIC. The bandwidth is 60MHz.

POWER SUPPLY SWITCHING

Power supply switching (Q412) turns on TX
POWER when the phone is in traffic mode and
supplies power to the circuits.

ISOLATOR

Isolator (I401) is used to reduce a reflected signal
to protect the power amp MMIC from being
damaged.

The signal output from BBA (Base Band ASIC)
should be a constant level. The TX IF AGC amp
(U404) controls power to keep the signal at a
desired level. Dynamic range is 85 dB, up gain
+40dB, and down gain -45dB.

POWER SUPPLY REGULATOR

The power supply regulator (U414) generates the
regulated power.

POWER SUPPLY REGULATOR

The power supply regulator (U413,U414) supplies
a regulated power to each part of transmitter.
U413 supplies 4.8V to Tx driver (Q413) and Power
Amp MMIC (U407). U414 supplies 4.2V to the
others.

Samsung Electronics 4-5

Circuit Description

4-4 Hands-Free Kit

Hands-free board is largely composed of car
adapter circuit and Hands-free circuit.

4-4-1 Car Adapter Circuit

POWER SUPPLY

Input power switching circuit : This circuit
includes Short protection circuit, and Power
switching control circuit. It supplies power for
HHP and hands-free kit.

+13.5V switching circuit (Q801, 802) : This circuit
switches power for power amplifier using MPU
mute signal.

HHP power circuit : This circuit is Switching
regulator. Input voltage is +13.6v, output voltage
is +5.8v.

Voltage detection circuit : Charging circuit is
designed to stop charging when the voltage of
battery is dropped.
The voltage of battery is entered to A/D converter
located in U703 #2.

Temperature detection circuit : The temperature
of battery is measured by missing NTC thermistor.
NTC themistor has a characteristics of Log-scale. It
obtains a linear characteristics by the parallel
connection of resistors.

4-4-2 Hands-free Circuit

POWER SUPPLY (U704,U808)

+5V is regulated by U704 for hands-free circuit,
and -5V is regulated by U808.

TX PATH

Vcc regulator (U704) : This circuit regulates Vcc
(+5V).

CHARGER CIRCUIT

This circuit charges battery pack by detecting the
temperature of battery, the slope of temperature,
the slope of the voltage of battery, and charging
time, etc.
During charging, the charger LED turn on red.
When charging is completed, the charger LED
turns on green.

Battery Type Capacity Charge Current Charge Voltage

S t a n d a r d 8 5 0 m A H 3 0 0 m A 6 . 2 V
E x t e n d e d 1 5 0 0 m A H 6 0 0 m A 6 . 7 V

The audio signal from external mic(JP705) flows
into U802 pin #11. U802 includes Amplifier and
Control circuit for hands-free operatin. U801A
amplifies input signal. Output signal is
transmitted to HHP.

RX PATH

Input audio signal cancels noise by difference
amplifier (U801c). U802 performs hands-free
action. The RX audio signal is input (U805). The
speaker drive amp (U804) amplifies the Rx audio
signal and the output of U804 goes out of speaker.

4-6 Samsung Electronics

4-5 Desk-Top Rapid Charger

Circuit Description

4-5-1 SMPS

1ST SWITCHING CIRCUIT

The AC current from AC plug transfers to a high­voltage DC through BD1, C2, and C3. TNR1 is AC
surge protector, and F1 is fuse to protect circuit
from overcurrent . The line filter composed of LF1
and C1 is used to protect from line noise and
switching noise.

The transferred DC voltage is switched by T1. 2nd
switching voltage is flattened into AC through D20
and C22, and filtered through L20 and C30.

The voltage is regulated through shunt regulator
U5, R28, R29.

2ND SWITCHING

The regulated voltage through 1st switching
circuit performs 2nd switching. Step-down
regulator is composed of Q20, U2, D22, L21, and
C25. Q20 performs high-speed switching
according to the output signal from U2. L21 stores
energy when the switching transistor turns on.
D22 is a fly-wheel diode and transfers the stored
energy when Q20 turns off.

4-5-2 Constant Current Circuit

U2 (TL494) has two error-amps. VREF (+5V) is
supplied to INV terminal (pin 15) of amp 1 and
N.INV terminal (pin 16) is connected to ground. It
causes the amp 1 output to be zero. In amp 2, the
reference voltage 2.0V is supplied to INV terminal
(pin 15) through R37 and R38, and the voltage
obtained in proportion to constant current is
supplied N.INV terminal (pin 16). The constant
current circuit also includes the shunt resistor R40,
and Q21 and U7.

FAST CHARGING (MASTER MODE)

The fast charging formula is shown below.

ICHG = x VREF (mA)

R40 x (R43 + RR)

For standard battery, RR is set with 680 ohm, and
for slim battery, 1 kohm is used.

SLOW (SLAVE MODE) AND TRICKLE
CHARGING

R39

<RR=330ߟ, VREF=2.0 V>

Voltage mode PWM IC U2 controls duty cycle
between the switching on and off of Q20. C30 and
R34 are parameter to determine the switching
frequency of U2.

Samsung Electronics 4-7

If batteries are installed both on front and rear port
of the desktop charger, the one installed in
advance performs fast charging while the other
installed later performs slow charging. In slave
mode, Q23 turns off. In trickle charging mode, Q24
turns off. The slow charging formula is shown
below.

ICHG = x VREF (mA)

R39

R40 x (R42)

<VREF=2.0 V>

Circuit Description

4-5-3 Master and Slave Mode

Status

Fastcharging on front port

Fastcharging on rear port
Front port master charging

Rear port slave charging
Rear port master charging

Front port slave charging
Fast charging on front port

Trickle charging on rear port
Fast charging on rear port

Trickle charging on front port
Trickle charging on both front and rear ports

Signal

MPU(11)

CUR_CTRL

HIGH LOW HIGH LOW LOW

LOW HIGH LOW LOW LOW

HIGH LOW LOW LOW HIGH

LOW LOW LOW HIGH LOW

HIGH LOW LOW LOW HIGH

LOW LOW LOW HIGH LOW

HIGH LOW LOW HIGH HIGH

4-5-4 Watch Dog and Reset Circuit

MPU U1 Reset pin is active in low state. U4 is used
as A/D reference voltage for MPU and whole
charging system, so the circuitry composed of
Q30-Q32 and D30 detects the voltage. In normal
state, Q31 turns on so U4 pin 3 becomes low. It
causes MPU Reset to be high. If an excessive
impulsive voltage is supplied to U4, Q30 turns on,
and U4 pin 3 becomes high. It causes MPU to be
reset.

MPU(4)
CHG_A

MPU(3)
CHG_B

MPU(13)

FRNT_GRN

MPU(9)

REAR_GRN

4-5-6 Temperature Detection

The battery temperature and ambient temperature
can seriously damage Ni-MH battery, so the
temperature is constantly detected by MPU. The
ambient temperature is detected by MPU pin 19
through R54, TH1, and R56. The battery
temperature is detected by R45, R46, and NTC,
and measured as A/D value by MPU pin 20.

4-5-7 Charging Voltage Detection

4-5-5 Timer

Timer is used to protect the battery from being
overcharged. The timer is set at initial routine. If
fast charge is not completed until maximum time
value, fast charge is stopped by the timer and it
moves to automatic trickle charge routing. This is
the final step to protect battery from excessive
charging and damage. There are four timers
available, and the default timer is 140 minutes.

Time (minute) Time-1 (RX1) Time-2 (RX2)

140 VCC VCC
210 GND VCC

280 VCC GND
350 GND GND

4-8 Samsung Electronics

The charging voltage of the battery is detected by
R47 and R48, and measured as A/D value by MPU

pin 18. The parameters, -ßEV, 0 ßEV, and Vmax,
used for checking charge level are also measured

by MPU.

4-5-8 Discharging Circuit

Discharging is available on the rear port only.
When MPU pin 14 acknowledges that the
discharging button is pressed, MPU pin 2 starts
discharging. Discharging is initiated immediately
when the button is pressed for over than 0.7
seconds within 30 seconds after battery installed. If
the voltage reaches 1 V/cell by discharge,
discharging stops, then fast charging starts
automatically.

4-6 Cigarette Lighter Adapter

4-6-1 Funtional Specification

Circuit Description

SUMMARY

This standard describes on the specifications of
CLA(Cigarette Lighter Adaptor) for the SCH-1000
of SAMSUNG.

CLA AS ADAPTOR AND CHARGER

¶UAdaptor

directly supplies power in order to operate
cellular phone independent of the battery pack.

¶UCharger

for the NiMH battery pack

ELECTRICAL SPECIFICATION

¶UInput Voltage : 11V to 16.5V DC

(normal voltage : 13.5V DC)

¶UOutput Current

- HHP POWER : supplies 100mA if cellular
phone mode is in stand_by state and 300mA

to 600mA in carrier_on state.

- Battery Charge Current : 390mA +/- 10%

(carrier_off) 10ßðæ1 0ßÃ(carrier_on, full_charge)

FUNCTIONS OF CLA

¶UProtection Circuit

Protection Circuit is the circuit against the
electrical stress which is occured at
unexpected conditions of the source power of
CLA unit such as reverse voltage or over­current.

¶UDetection of cellular phone

If cellular phone is connected to CLA, the
CLA lamp is on to display whether charge
will be done normaly or not.

¶UDetect Carrier-On

In the case of Carrier-On, CLA detects the
resistance of the Cellular Phone and reduces
the charge current.

¶UDetect Full-Charge

If the temperature of the battery pack is
higher than the temperature outside of the
cellular phone, CLA detects the battery fully
charged and the state will be converted to the
Trickle Charge.

CLA CURL CABLE CONNECTION

¶UOutput Voltage (when 2K•ÿ is loaded to the

battery charge terminal)

- Battery Charge Terminal : 5.8°æ0.5V

- HHP POWER Terminal : 5.8V(+/- 0.3V)

¶URipple & Noise : 50mVp-p
¶UNormal Fuse Capacity : 250V, 2A
¶UCharge Time : 3Hrs. at 850mAh6Hrs. at

1500mAh

ENVIRONMENTAL SPECIFICATION

¶UTemperature

- Operating Temperature : 0°… to 50°…

- Storage Temperature : -20°… to 85°…

¶UHumidity

- Operating Humidity : 5% to 90%

- Storage Humidity : 5% to 95%

PIN NO(CLC) Description PIN NO(HHP)
#1 HHp Power 12 or 13
#2 BATT 16
#3 Thermistor 15
#4 C/F 3
#5 GND 2 or 4 or 6

Samsung Electronics 4-9

Circuit Description

4-6-2 Schematic Description

DC-DC CONTROLLER

KA7500B(U1) is DC-DC Controller. It reads the
voltage difference between E1I+ Port and E1I- Port
and controls time to turn on Q1. E2I+ and E2I­turn on Q1 in the same way. U1 also supplies +5V
of Reference Voltage(Vref).

STATIC CURRENT

E1I- Port of U1 detects about 1.25V untill Full­Charge and controls the TURN ON time of Q1 in
order to detect 1.25V at E1I+ Port. To make the
E1I+ Port detect 1.25V continuously, 0.19V of
voltage reduction will be generated on R4. At the
equation of V=I*R, the current of R4 is around
390mA and it will be the charge current.

BATTERY CHARGE CURRENT CUTTING BY
RELATIVE TEMPERATURE

Although every battery sample applied to the
SCH-1000 has almost the same battery
temperature at Full-Charge, it varies according to
the relative temperature.
So the battery temperature at Full-Charge may be
different according to the temperature around the
cellular phone.

PREVENT CHARGE CIRCUIT IN THE CASE
OF MOBILE PHONE CARRIER-ON

In the case of Mobile Phone carrier-on, the voltage
loaded on PIN-13 of U3D is lower than that of
PIN-12. So PIN-14 ouputs HIGH and Q3 is TURN
ON again. It results to the Prevent Charge.

LED-DRIVING CIRCUIT

When battery is inserted to CLC, the voltage
loaded to PIN-2 of U3A is lower than that of PIN-3
and PIN-1 outputs HIGH. This TURN ON Q7 and
drives LED.

If Full-Charge occures at 25°…, the voltage of U3C
to which the battery thermistor is connected is

around 2.11V and the voltage of the parallel
resistance of Th1 and R18 is about 2.11V. PIN 8 of
U3C will be HIGH and turn on Q3 if the
temperature is up. This generates the voltage
detected at E1I- of U1 around 0.1V and the charge
current reduces to 40mA. If Full-Charge occurs at
high temperature and low temperature, the battery
temperature varies and the voltage decline of Th1
and R18 relatively varies. So the battery Full­Charge condition will be fulfilled.

4-10 Samsung Electronics

4-7 Travel Charger

Circuit Description

4-7-1 Input Filter and Regulator

The AC input converts to a high-voltage DC
through overcurrent protector F1 and F2, surge
protector VA1, noise eliminator CO1 and LF1, and
regulator D1 and C3.

4-7-2 Switching Controller and

Transformer

DC voltage is biased to the gate of Q1 through
R3-R7, resulting Q1 to be on. When the current is
supplied to the primary winding of T1, the gate
voltage of Q1 is increased.

The voltage detected by R2 is biased to the base of
Q2 through R10 and C7. It turns Q2 on. The gate
voltage of Q1 is reduced so that Q1 turns off. The
flyback current transfers to the secondary
winding.

4-7-3 Feedback

4-7-4 Battery Charging

Without battery installed, Q24 turns on. It turns

LED off. The output status of U23 and U24 are as
follows:

OUT-A OUT-B Q21 Q20
U23 L L
U24 L L OFF OFF

With battery installed, and when the output
voltage of U23A pin 3 is smaller than pin 2, the
output status of U23 and U24 are as follows. Q24
turns off, the LED is lit in red.

OUT-A OUT-B Q21 Q20
U23 L L
U24 H H OFF OFF

When the battery voltage of pin 3 of U23A is
greater than pin 2, Q21 turns off, the output of
U23A becomes low, the output status of U23 and
U24 are as follows:

The transferred current is rectified and flattened
by D20, C21 and C22. If there is no battery
installed or Q2 turns off, the current is biased to
U21 through R26 and R27, then applied to OP1
according to the value set through R27-R29. It
controls the bias voltage of Q2 base. It causes the
output voltage to be 8.0V.

OUT-A OUT-A Q21 Q20
U23 H H
U24 H H ON ON

When Q20 and Q21 turn on, the battery is charged.

The output voltage detected by R21 is increased
until the output voltages of U22A pin 6 and pin 5
are the same level. When the output voltage of pin
5 becomes greater than that of pin 6, U22 becomes
high, resulting U21 reference voltage to be high.
When the OP1 current increases, Q2 turns on, Q1
turns off, and the output voltage is reduced.

The battery voltage is detected by U23B pin 5.
U23B compares the voltage with reference voltage
in pin 6, and remains low status until the voltage
reaches the reference voltage. It causes U24A to be
remained high.

Samsung Electronics 4-11

Circuit Description

When the battery is being charged, U23B becomes
high and the output voltage of U24A pin 2 returns
to the reference.

When the battery is fully charged, the battery
temperature is increased. After detecting the
temperature, if the U24A pin 2 is greater than pin
3, the output status of U23 and U24 are as follows:

OUT-A OUT-B Q21 Q20
U23 L H
U24 L H OFF OFF

When charging is completed, 20mA trickle current
flows through R24, R25, and D21. Q24 turns on,
and red LD1 turns off. Latch circuit operates so
that U24A remains in low and trickle current is
supplied to the battery. The latch is released when
AC power turns off or the battery is removed from
the main body.

4-12 Samsung Electronics

5. Test Procedure

5-1 List of Equipment

¶UDC Power Supply
¶UTest Jig
¶UTest Cable
¶UCDMA Mobile Station Test Set HP8924C, HP83236B, CMD-80, etc
¶USpectrum Analyzer (include CDMA test mode) HP8596E

5-2 Configuration of Test

5-2-1 Hand Set

5-2-2 Hand-Free

Samsung Electronics 5-1

Test Procedure

5-3 Test Procedure

5-3-1 Change to Test Mode

1. To change the phone from Normal Mode to test
Mode, You should enter the following keys.

" 4 7 * 8 6 9 # 1 2 3 5 "

2. The command ° ∞0 1"(Suspend) is entered to start

test.

3. To finish the Test Mode, You should enter the

command "0 2".

5-3-2 Channel Selection and Tx Power

Output level Control

1. You should change the phone from Normal

Mode to Test mode

2. The command ° ∞0 1"(Suspend) is entered to start

test.

3. You should enter the following keys.
" 0 9, 0 5 2 5, #, 0 7, 3 4, 7 1, 4 7 5, #"

¶UIf you enter the command "0 9", You can select

the channel

ex) 0 9 X X X X (means channel number)

¶UThe command "0 7°±means Carrier On (Carrier

Off : ° ∞0 8°±)

¶UIf you enter the command "3 4", You can

spread the carrier.

¶UIf you enter the command "7 1", You can

control the power output level. Following
under-bar means AGC code. And you can
control the power output level using Volume
Up/Down Keys.

ex) 7 1 X X X

4. After enter the command "7 4" and control the

Tx Power Output Level to be 0.0dBm using
Volume Up/Down keys, press "STO" key to
store Data in EEPROM.

5-2 Samsung Electronics

Test Procedure

5-4 Test Command Table

Command No. Test Command Description
(OP, AB, RB)

01(1F, 0, 0) T_SUSPEND_I Terminate the normal mode, enter to the test mode.
02(3F, 0, 0) T_RESTART_I Terminate the test mode, enter to the normal mode.
03(FD, 0, 0) T_SAVE_VAL_I Save value in EEPROM. (Only for Auto test)
04(1D, 0, 1) T_GET_MODE_I Get mode. (CDMA or FM)
05(1C, 1, 0) T_SET_MODE_I Set mode to CDMA or FM. (Only for Auto test)
06(1E, 0, 0) T_WRITE_NV_I Write an EEPROM item. (one of the NV items)
07(81, 0, 0) T_CARRIERON_I Turn the carrier on.
08(82, 0, 0) T_CARRIEROFF_I Turn the carrier off.
09(83, 4, 0) T_LOADSYN_I Set the synthesizer to the channel specified by ch_ data.
10(84, 1, 0) T_PWRLEVEL_I Set the RF power attenuation to the specified value.
11(85, 0, 0) T_RXMUTE_I Mute the receive-audio signal.
12(86, 0, 0) T_RXUNMUTE_I Unmute the receive-audio signal.
13(87, 0, 0) T_TXMUTE_I Mute the transmit-audio signal.
14(88, 0, 0) T_TXUNMUTE_I Unmute the transmit-audio signal.
16(8F, 0, 0) T_STON_I Turn on ST.
17(90, 0, 0) T_STOFF_I Turn off ST.
22(91,96,96) T_SNDNAM_I Display and send NAM information.
23(95, 3, 4) T_SNDVERSION_I Display and return S/W version.
24(9F, 7, 8) T_SNDESN_I Display and return ESN.
25(92, 0, 0) T_BACKLIGHT_ON_I Turn on the backlight.
26(93, 0, 0) T_BACKLIGHT_OFF_I Turn off the backlight.
27(96, 0, 0) T_LAMP_ON_I Turn on the LAMP.
28(97, 0, 0) T_LAMP_OFF_I Turn off the LAMP.
29(9A, 0, 0) T_REBUILD_I Rebuild EEPROM.
30(9D,15, 0) T_PLINE_I Display and return production date.
32(A0, 1, 0) T_SATON_I Turn on SAT.
33(A1, 0, 0) T_SATOFF_I Turn off SAT.
34(A2, 0, 0) T_CDATA_I Continuously send TX control data.
35(A3, 0, 0) T_VOLUME_UP_I Increase value of the last command. (Only for autotest)
36(A4, 0, 0) T_VOLUME_DOWN_I Decrease value of the last command. (Only for autotest)

42(AA, 1, 0) T_DTMFON_I Activate dtmf generator with keycode.
43(AB, 0, 0) T_DTMFOFF_I Deactivate DTMF generator.
44(B0, 0, 0) T_COMPANDORON_I Turn on compandor.
45(B1, 0, 0) T_COMPANDOROFF_I Turn off compandor.
50(B6, 4, 0) T_H_LIST_I History Channel.
57(BC, 0, 0) T_MIC_ON_I Mic path on.
58(BD, 0, 0) T_MIC_OFF_I Mic path off.
59(BE, 0, 0) T_ALLPATH_I Set RX Path, TX Path Unmute to Earpiece.
67(C6, 3, 6) T_READ_BATT_I Reads Low-Battery in the standby, talk.

Samsung Electronics 5-3

Test Procedure

Command No. Signal. Name Description
(OP, AB, RB)

68(C8, 0, 3) T_VBATT1_I Set the low battery position in the standby.
69(C9, 0, 3) T_VBATT2_I Set the low battery position in the talking.
70(CA, 3, 0) T_WRITE_BATT_I Write low battery level value to NVM.
71(D1, 3, 0) T_CDMA_TXADJ_I Change PDM TX AGC in CDMA.
72(D2, 3, 0) T_FM_TXADJ_I Change PDM TX AGC in FM.
73(D3, 1, 0) T_SET_PA_R_I Set PA R1, R0 in CDMA.
74(D4, 3, 0) T_TXADJ_0DBM_I Set TX AGC ADJ for 0dBm power.
75(D5, 0, 3) T_READ_RSSI_I Read a RSSI.
76(D6, 3, 0) T_WRITE_RSSI_I Writes RSSI.
77(D7, 0, 3) T_READ_TEMP_I Read Temp.

79(D9, 1, 0) T_BUZZER_ON_I Buzzer On at DTMF 0 key.
80(DA, 0, 0) T_BUZZER_OFF_I Buzzer off.

81(E3, 0, 0) T_VOC_PCMLPON_I Play a PCM LOOP BACK.
82(E4, 0, 0) T_VOC_PCMLPOFF_I Play off a PCM LOOP BACK.
84(E6, 3, 0) T_CD_MAX_LIMIT_I CDMA MAX limit.

85(E7, 0, 0) T_SPEAKER_ON_I Turn on the speaker path.
86(E8, 0, 0) T_SPEAKER_OFF_I Turn off the speaker path.

87(E9, 0, 0) T_FM_LOOP-TEST_I Play a PCM FM loopback.
88(EA, 3, 0) T_TRK_ADK_I TRK LOCAL ADJUST.

89(EB, 3, 0) T_CD_TRK_ADJ_I CDMA TRK LOCAL ADJUST.
90(F0, 3, 0) T_CDMA_LOW_CH_HIPWR_I Setting the volume for LOW CH highpwr. (+18dBm)
91(F1, 3, 0) T_CDMA_LOWMID_CH_HIPWR_I Setting the volume for LOWMID CH highpwr. (+18dBm)
92(F2, 3, 0) T_CDMA_MIDDLE_CH_HIPWR_I Setting the volume for MIDDLE CH highpwr. (+18dBm)
93(F3, 3, 0) T_CDMA_LOW_CH_LOPWR_I Setting the volume for LOW CH lowpwr. (-41dBm)
94(F4, 3, 0) T_CDMA_LOWMID_CH_LOPWR_I Setting the volume for LOWMID CH lowpwr. (-41dBm)
95(F5, 3, 0) T_CDMA_MIDDLE_CH_LOPWR_I Setting the volume for MIDDLE CH lowpwr. (-41dBm)
96(F6, 3, 0) T_CDMA_HIGHMID_CH_LOPWR_I Setting the volume for HIGHMID CH lowpwr. (-41dBm)
97(F7, 3, 0) T_CDMA_HIGH_CH_LOPWR_I Setting the volume for HIGH CH lowpwr. (-41dBm)
98(F8, 3, 0) T_CDMA_HIGHMID_CH_HIPWR_I Setting the volume for HIGHMID CH highpwr. (+18dBm)
99(F9, 3, 0) T_CDMA_HIGH_CH_HIPWR_I Setting the volume for HIGH CH highpwr. (+18dBm)

¶S

OP: Operation Command Number
AB: Input Argument Byte Number
RB: Return Byte Number

5-4

Samsung Electronics

6. Troubleshooting

6-1 Logic Section

6-1-1 No Power

Samsung Electronics 6-1

Troubleshooting

6-1-2 Abnormal Initial Operation (Normal +3.3V voltage source)

6-2 Samsung Electronics

6-1-3 Abnormal Backlight Operation

Troubleshooting

Samsung Electronics 6-3

Troubleshooting

6-1-4 Abnormal Key Data Input

6-4 Samsung Electronics