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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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

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:									SEND END PWR
	∙ 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

AF778

∙ Minute Minder Selection ∙ Auto area code

∙Emergency numbers

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	4.8 oz.	4.9 oz.	137 g		139 g
(w/battery)

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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

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.

1

2

READY

3

	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*	Alert option (Menu 16) is set to vibrate only, and there is
	an incoming call, or you have answered and incoming
	call.
Orange – Steady*	Alert option – vibrator only. Battery charging.
No light	Phone is OFF, no signal is available, or phone is in
	CHARGING ONLY mode.
* AF778 Only

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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

HELICAL COIL

CONTACT FERRULE

ANTENNA BASE GROUND CONTACT

(NOT CONNECTED WHEN RETRACTED)

ANTENNA MAST

BOTTOM CRIMP CONTACT (ANTENNA GROUND)

PCB

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