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Samsung Electronics - Contents may change without notice.
5-8
Circuit Description
5-5 Hands-Free Kit
5-5-1 Charging Circuit
A constant voltage is used for the hands-free kit.
This circuit converts DC 12V input current to 8.4V
DC to charge the battery. When the battery is fully
charged, the charge current drops and the circuit
operates as a constant voltage.
5-5-2 u-Processor
Micro processor controls charging power and
charging current to protect the phone. It also
allows to communicate with a HHP, and to con-
vert from hands-free mode to private mode, and
vice verse. It adjusts speaker volume at 8 steps
and attenuates echo and noise occurred during
conversation.
5-5-3 Speaker circuit
This circuit eliminates HHP noise, and controls
the sound quality and speaker volume using ana-
log C-mos IC which checks the speaker signal up
to 8 steps. 5W audio amplifier amplifies the speak-
er signal.
5-5-4 Microphone Circuit
This circuit separates ground to eliminate the
noise occurring from the HHP antenna and micro-
phone. u-processor controls this circuit to attenu-
ate echo which may occur in Land side.
CURRENT DETECTION CIRCUIT : R5, R6,
R11, R12, HIC
Battery charging current is changed voltage
through R5, R6, R11, R12. This voltage inputed
u-COM to 16 times amplifiered through HIC.
VOLTAGE DETECTION CIRCUIT : HIC
u-COM A/D through HIC pin 12, 13 detected
voltage.
BATTERY TEMPERATURE DETECTION CIR-
CUIT : HIC, TH1
Battery temperature detection determined
temperature by ues of thermistor registor
variation of THI by HIC.
CURRENT LIMIT CIRCUIT : HIC
When soft-change, current detection circuit
limited current flow to battery, reference voltage
more than detected current, detected current and
HIC internal reference voltage.
Summary of Contents for SCH-211
Page 2: ...Samsung Electronics Co Ltd GH68 00335A ELECTRONICS ...
Page 3: ...Samsung Electronics Contents may change without notice 1 Specification ...
Page 5: ...Samsung Electronics Contents may change without notice 1 2 General Introduction MEMO ...
Page 11: ...Samsung Electronics Contents may change without notice 2 6 Specification MEMO ...
Page 17: ...Samsung Electronics Contents may change without notice 3 6 Installation MEMO ...
Page 47: ...Samsung Electronics Contents may change without notice 6 10 Troubleshooting MEMO ...
Page 65: ...Samsung Electronics Contents may change without notice 8 4 PCB Diagrams Bottom View ...
Page 93: ...Samsung Electronics Contents may change without notice 9 24 Electrical Parts List MEMO ...
Page 113: ...Samsung Electronics Contents may change without notice 10 20 Block Circuit Diagrams MEMO ...