ERICSSON AF738, AF778 Technical Description CH2
Technical Description EN/LZB 119 2506 R1A
Chapter 2
Technical Description
Ericsson Cellular Phone AF738
AF778
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EN/LZB 119 2506 R1A Technical Description
SUBJECT .................................................................................... PAGE
General ................................................................................................................... 2-1
Mechanical........................................................................................................2-2
Table 2-1. Phone Dimensions ............................................................................2-2
Keypad..............................................................................................................2-3
Figure 2-1.Keypad.............................................................................................2-3
Side Volume Keys.............................................................................................2-4
Figure 2-2. Side Volume Keys...........................................................................2-4
LCD..................................................................................................................2-4
Figure 2-3. LCD Display ...................................................................................2-4
Table 2-2. LCD Display Areas...........................................................................2-4
Top Indicator.....................................................................................................2-5
Table 2-3. Top Indicator Functions....................................................................2-5
Vibrator Motor (AF778 Only)............................................................................2-6
Retractable Antenna ..........................................................................................2-6
1/4 Wave Antenna Operation.........................................................................2-6
Figure 2-4. AF778 1/4 Wave Antenna Connections............................................2-7
1/2 Wave Antenna Operation (AF778)...........................................................2-7
Figure 2-5.1/2 Wave Antenna Connections........................................................2-8
Transceiver PCB and Component Layout............................................................. 2-9
Major Components................................................................................................2-10
Figure 2-6. PCB Component Layout................................................................2-10
Table 2-4. Component Table............................................................................ 2-11
Figure 2-7. Block Diagram ..............................................................................2-13
Radio Section.........................................................................................................2-15
General............................................................................................................ 2-15
Table 2-5. Frequencies..................................................................................... 2-15
Duplexer..........................................................................................................2-16
Receiver..........................................................................................................2-16
Receive Front End .......................................................................................2-17
IF Section.................................................................................................... 2-17
Synthesizer......................................................................................................2-18
VCTCXO.................................................................................................... 2-18
BERTINDY.................................................................................................2-19
RX (Main) Synthesizer ................................................................................2-19
TX (Auxiliary) Synthesizer..........................................................................2-20
MALIN .......................................................................................................2-20
Transmitter......................................................................................................2-20
Power Amplifier.......................................................................................... 2-20
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Technical Description EN/LZB 119 2506 R1A
SUBJECT......................................................................................................... PAGE
Logic Section......................................................................................................... 2-21
Processor/Control Interface............................................................................. 2-21
GUSTAV.................................................................................................... 2-22
6303 Microprocessor................................................................................... 2-22
ROM .......................................................................................................... 2-22
RAM .......................................................................................................... 2-22
Bus Interface............................................................................................... 2-22
Decoder...................................................................................................... 2-22
Serial Interface ............................................................................................ 2-22
External Ports ............................................................................................. 2-22
Watchdog On/Off........................................................................................ 2-23
Beep, Alarm, Ring (BAR)........................................................................... 2-23
Clock Generator .......................................................................................... 2-23
Silent Ring (AF778 Only)........................................................................... 2-23
Internal Ports .............................................................................................. 2-23
Modem ....................................................................................................... 2-24
Baudclock................................................................................................... 2-24
Memories........................................................................................................ 2-24
RAM .......................................................................................................... 2-24
ROM .......................................................................................................... 2-24
EPROM (Flash).......................................................................................... 2-25
EEPROM.................................................................................................... 2-25
User Interface ................................................................................................. 2-26
LCD ........................................................................................................... 2-26
Keyboard.................................................................................................... 2-26
Buzzer ........................................................................................................ 2-26
Illumination ................................................................................................ 2-27
Vibrator Motor (AF778 Only)..................................................................... 2-27
Audio (Baseband) Section............................................................................... 2-27
Receive Audio ............................................................................................ 2-27
Transmit Audio........................................................................................... 2-27
Power Supplies............................................................................................... 2-28
Regulators................................................................................................... 2-28
Reset........................................................................................................... 2-28
On/Off Control............................................................................................ 2-28
Transient/ESD Protection............................................................................ 2-29
Charging Circuit............................................................................................. 2-29
Rapid Charging........................................................................................... 2-30
Figure 2-8. Rapid Charging ............................................................................. 2-30
Trickle Charging......................................................................................... 2-30
Connections On The Transceiver Board.............................................................. 2-31
Antenna Connector......................................................................................... 2-31
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EN/LZB 119 2506 R1A Technical Description
SUBJECT.......................................................................................................... PAGE
Battery Contacts.............................................................................................. 2-31
Speaker Connector...........................................................................................2-31
LCD Contacts.................................................................................................. 2-31
Microphone Connector....................................................................................2-31
Vibrator Connector (AF778 Only) ...................................................................2-31
Antenna Ground Strap (AF778 Only)...............................................................2-31
System Connector............................................................................................2-32
Figure 2-9. System Connector.......................................................................... 2-32
Table 2-6. System Connector Signals ...............................................................2-32
Specifications.........................................................................................................2-33
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Technical Description EN/LZB 119 2506 R1A
AF778
END PWR
General
The Ericsson AF738 and AF778 cellular telephones are small, lightweight phones
operating at 4.8v, powered by a 4-cell Nickel Metal Hydride (NiMH) battery. They
are class III cellular telephones for use with the AMPS cellular network.
Features of the phone include:
• Compact and lightweight
• Retractable Antenna
• Power-on greeting
• Multilingual with Language menus
• Built-in charging circuitry
• Authentication capable (system dependent)
• Caller line ID* (CLI)
• Voice mail message waiting indicator* (MWI)
• Negative SID Navigation
• Multiple NAMS (up to four)
• Multiple memory locations:
• Standard memory
• Last 10 Numbers dialed
• 1 Last 0 Caller Line IDs (CLI)
∗
• 5 Scratch Pad Memory Locations
• 5 Secure Memory Locations
• Dual-tone multi-frequency (DTMF) dialing
• RSSI and battery capacity indicators
• Ability to connect to external handsfree equipment
• Meets FCC Hearing Aid Compatibility Standards
• Electronic Lock/Call Restrictions
• Ring tone and volume selection
• System selection
• Different answering methods
• Microphone volume selection
• Auto retry on system busy
• Backlight selection
• Minute Minder Selection
• Auto area code
• Emergency numbers
SEND
∗
Requires software version R5A or higher
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EN/LZB 119 2506 R1A Technical Description
• Call time counters
• Silent call alert with vibrator (AF778 only)
• ½ wave up, ¼ wave down antenna
Mechanical
Refer to Table 2-1 for phone dimensions. The telephone consists of:
• A transceiver
• A removable battery
• A removable, retractable antenna
• A removable, active flip
Table 2-1. Phone Dimensions
English Metric
AF738 AF778 AF738 AF778
Length 4.17 in. 4.17 in. 106 mm 106 mm
Width 1.97 in. 1.97 in. 50 mm 50 mm
Thickness .94 in. .94 in. 24 mm 24 mm
Weight
(w/battery)
4.8 oz. 4.9 oz. 137 g 139 g
2-2
Technical Description EN/LZB 119 2506 R1A
The transceiver consist of:
• Front cover (with speaker)
• Back cover
• Keypad
• Printed circuit board (PCB)
• LCD/lightguide assembly
• Vibrator (AF778 only)
Keypad
The keypad is rubber with soft keys. See Figure 2-1. It is backlit, which makes it
possible to operate the phone in the dark. The backlight function has four possible
settings:
• On 10 seconds
• On 20 seconds
• On (when connected to external power only)
• Off
The END/PWR/NO key is not scanned, as are the other keys. It is connected to a
power switch such that microprocessor power is forced on when this key is held
down. The microprocessor can also see this key indirectly to implement the OFF
function.
SEND
END PWR
YES
NO
MEM CLR MENU
Figure 2-1. Keypad
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EN/LZB 119 2506 R1A Technical Description
READY
1
2
3
Side Volume Keys
See Figure 2-2. The volume keys are separate from the main keypad. They are push
button switches mounted on the side of the phone near the upper left corner of the
LCD.
SIDE
VOLUME
KEYS
Figure 2-2. Side Volume Keys
LCD
The phone has a 1-line LCD containing icons as well as numbers and alpha
characters. See Figure 2-3 and Table 2-2.
Figure 2-3. LCD Display
Table 2-2. LCD Display Areas
Fig.
Ref. Description Function
1 Number/Character Display Displays number or character entered
2 Battery Strength Icon Displays relative strength of battery
3 Signal Strength Indicator Displays signal strength (up to 5 bars)
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Technical Description EN/LZB 119 2506 R1A
Top Indicator
A multi-color light emitting diode (LED) is located on the top front of the phone.
Refer to Table 2-3.
Table 2-3. Top Indicator Functions
Light Indicates
Green - slow blink Ready. Phone is ready to make/receive calls.
Green - fast blink There is an incoming call or you have answered an
incoming call.
Green - steady Battery is charging and phone is ON.
Red - blinking Battery power is low.
Orange – Slow blink* Alert Option (Menu 16) is set to vibrate only.
Orange – Fast blink*
Orange – Steady* Alert option – vibrator only. Battery charging.
No light
* AF778 Only
Alert option (Menu 16) is set to vibrate only, and there is
an incoming call, or you have answered and incoming
call.
Phone is OFF, no signal is available, or phone is in
CHARGING ONLY mode.
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EN/LZB 119 2506 R1A Technical Description
Vibrator Motor (AF778 Only)
The AF778 cellular phone has a vibrating motor as an option for silent ring
indication. When the vibrating motor is activated (Menu 16), the unit will vibrate
three times when receiving an incoming call. It will also vibrate when the phone is
first turned on.
Retractable Antenna
Both the AF738 and the AF778 feature a retractable antenna. The AF738 is 1/4 wave
in both the up (extended) and the down (retracted) positions. The AF778 is 1/4 wave
in the down position and 1/2 wave in the up position.
The AF778 uses a new design consisting of a molded antenna base with a metallic
contact ferrule, and a retractable whip consisting of a helical coil, an overmolded
whip cap, and an exposed metallic upper contact ring.
This design allows the antenna to operate in 1/4 wave and 1/2-wave modes while
requiring a single RF feed.
1/4 Wave Antenna Operation
In the retracted position, the AF778 operates in 1/4 wave mode. The helical coil
contacts directly to the ferrule on the antenna base. The contact ferrule makes a direct
connection to the RF feed on the antenna connector. This in turn provides a path to
the RF feed point on the PCB. The end of the whip is grounded to the PCB via a
grounding clip. See Figure 2-4.
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Technical Description EN/LZB 119 2506 R1A
PCB
HELICAL COIL
ANTENNA BASE
CONTACT FERRULE
GROUND CONTACT
(NOT CONNECTED WHEN RETRACTED)
ANTENNA MAST
BOTTOM CRIMP CONTACT
(ANTENNA GROUND)
Figure 2-4. AF778 1/4 Wave Antenna Connections
1/2 Wave Antenna Operation (AF778)
The helical connection to the PCB is broken when the antenna is extended. The
contact ferrule, however, remains in contact with the RF feed contact on the PCB.
The connection from the RF contact on the PCB and the antenna is made (via a
capacitive coupling) through a dielectric insulating material to the antenna rod. Since
the antenna mast is connected to the top helical coil, the antenna becomes an
effective 1/2-wave antenna.
The bottom crimp contact on the antenna mast mates with shunt inductor-to-ground
contact when the antenna is extended. To prevent the bottom crimp from shorting to
the RF feed, the overmolded stepped insulator provides insulation between the two
points. The coaxial connection to the NiTi rod and the shunt inductor make up the
matching network. See Figure 2-5.
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EN/LZB 119 2506 R1A Technical Description
PCB
Figure 2-5. 1/2 Wave Antenna Connections
2-8
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