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Technical Description
Ericsson Handheld Telephone 1341-B
Technical Description
2
Technical Description
Contents
Design ________________________________________________ 6
Mechanical ______________________________________________ 6
Electronics ______________________________________________ 6
Functional Overview __________________________________ 7
Reception _______________________________________________ 7
Transmission_____________________________________________ 8
Automatic Frequency Control (AFC)__________________________ 8
Low Frequency (Audio) Processing ___________________________ 8
Companding _____________________________________________ 9
Logic ___________________________________________________ 9
Power Supply ___________________________________________ 9
Functional Blocks and Units Description ____________ 10
Frequency Generation_____________________________________ 10
VCTCXO____________________________________________ 10
Rx Frequency Synthesizer_______________________________ 10
Tx Frequency Synthesizer _______________________________ 12
Transmitter _____________________________________________ 12
Driver Stage__________________________________________ 13
Control of Output Power ________________________________ 13
Receiver _______________________________________________ 13
RF-Stage ____________________________________________ 13
IF Stage _____________________________________________ 13
Power Supply Monitoring _________________________________ 14
Power Supply: Charging __________________________________ 15
Control Logic ___________________________________________ 15
System Interface ______________________________________ 16
Processor ____________________________________________ 16
Display _____________________________________________ 16
Keyboard ____________________________________________ 16
Audio Processing ________________________________________ 17
Audio Circuits in Transmission___________________________ 17
Audio Circuits in Reception _____________________________ 18
ON/OFF-Button _________________________________________ 18
Continued on next page
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Technical Description
The Major IC Packages ______________________________ 19
CARL ________________________________________________ 19
Built-in Microprocessor _______________________________ 19
Serial Port (in Processor) _______________________________ 20
ROM ______________________________________________ 20
RAM ______________________________________________ 20
Clock Generator _____________________________________ 20
Modem ____________________________________________ 20
SAT ______________________________________________ 20
BAR Generator ______________________________________ 21
Serial Interface ______________________________________ 21
IF Counter _________________________________________ 21
Ports ______________________________________________ 21
Baud Clock__________________________________________ 21
BERTRAM ____________________________________________ 22
Serial interface _______________________________________ 22
ADC ______________________________________________ 22
Digital inputs _______________________________________ 22
Digital outputs ______________________________________ 23
DAC ______________________________________________ 23
AFC amplifier ______________________________________ 23
LINA _________________________________________________ 23
Duplex Filter ___________________________________________ 24
EPROM _______________________________________________ 24
EEPROM______________________________________________ 24
Interface Block _________________________________________ 24
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Technical Description
The Ericsson Handheld Telephone 1341-B is a pocket telephone for opera-
tion in the ETACS system.
Special features are: