Ericsson EF738 Service Manual page 30

Overview __________________________________________ 7
Basic Building Blocks ______________________________________ 8
Transceiver Block Diagram _________________________________ 9
PCB ____________________________________________________ 10
Mechanical Design __________________________________11
Man Machine Interface (MMI)_______________________ 12
Keypad _________________________________________________ 12
Display _________________________________________________ 12
Acoustic Signals __________________________________________ 12
Top LED Indicator _______________________________________ 12
Radio Design ______________________________________ 13
General Overview ________________________________________ 13
Antenna Connector ___________________________________________ 13
Antenna Filters ______________________________________________ 13
Receiver Part________________________________________________ 14
Receiver Front End ________________________________________ 14
IF Part __________________________________________________ 14
Receiver Back-End ________________________________________ 15
Synthesizer _________________________________________________ 16
Programming _____________________________________________ 16
Power___________________________________________________ 16
Lock Detect ______________________________________________ 16
VCTCXO __________________________________________________ 17
Transmitter _________________________________________________ 18
TX Blocks _______________________________________________ 18
MALIN ____________________________________________________ 19
TX-IF VCO ______________________________________________ 19
TX Mixer ________________________________________________ 19
TX Modulation ___________________________________________ 19
TX-IF Frequency Control ___________________________________ 19
Programmable Prescaler ____________________________________ 19
Power and Charging Design _________________________ 20
Regulators ______________________________________________ 20
Reset ___________________________________________________ 21
On/Off Control __________________________________________ 21
Charging Circuitry _______________________________________ 21
Transient/ESD Protection__________________________________ 22
Off Current Draw ________________________________________ 22
User Interface _____________________________________ 23
Illumination _____________________________________________ 23
Buzzer __________________________________________________ 23
LCD Display_____________________________________________ 23
Keypad _________________________________________________ 23
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Contents
Technical Description
3