Samsung Electronics - Contents may change without notice.
6-5
Circuit Description
6-2 Receiver Section
LOW NOISE AMPLIFIER (LNA)
The low noise amplifier featuring 1.5dB and 16 dB
gain amplifies a weak signal received from the
base station to obtain the optimum signal level.
DOWN CONVERTER (MIXER)
First local signal is applied to this down converter.
The down converter transfers the signal amplified
at the LNA into 85.38 MHz IF signal. 85 MHz IF
signal is made by subtracting 881 12.5 MHz RF
signal from 966 12.5MHz first local signal.
RX IF AUTOMATIC GAIN CONTROLLER
(AGC) AMP
85.38 MHz IF signal is applied to IF AGC amp, the
IF AGC output level is applied to BBA (Baseband
Analog ASIC). The IF AGC amp (U302) keep the
signal at a constant level by controlling the gain.
Dynamic range is 90 dB, up gain +45dB, and down
gain -45dB.
RF BAND PASS FILTER (BPF)
The RF BPF (F302) accepts only a specific
frequency (881 12.5MHz) from the signal
received from the mobile station. The band width
is 25 MHz.
IF SAW BAND PASS FILTER FOR AMPS
IF SAW BPF (F304) is used for AMPS system
having 30 kHz channel spacing and 15 kHz
band width. The filter also eliminates the image
product generated at the mixer.
IF SAW BAND PASS FILTER FOR CDMA
IF SAW BPF (F303) is used for CDMA system
having 1.23 MHz wide band and 630 kHz band
width. The filter also eliminates the image product
generated at the mixer.
BUFFER
Buffer (Q342) amplifies signal to be applied to the
local input of the down converter (U301) when a
phase is locked between VCO (U341) and PLL IC
(U342).
VOLTAGE CONTROLLED OSCILLATOR
The VCO (U341) generates the signal having 966
MHz center frequency and 12.5 MHz deviation
with the voltage control. PLL IC (U342) controls
this signal.
PHASE LOCKED LOOP (PLL)
Input reference frequency is generated at
VC_TCXO (U343) and the divided signal is
generated at VCO (U341). PLL compares the two
signals and generates the desired signal with a
pre-programmed counter which controls voltage.
VOLTAGE CONTROLLED TEMPERATURE
COMPENSATED CRYSTAL OSCILLATOR
It provides 19.68 MHz reference frequency to the
mobile main set. A correct frequency tuning is
made by the voltage control.
THERMISTOR
The thermistor (U371) detects temperature. It is
used to compensate active component
characteristics due to the temperature difference.
Summary of Contents for SCH-210
Page 2: ...Samsung Electronics Co Ltd GH68 60756A ...
Page 4: ...1 2 Samsung Electronics Contents may change without notice General Introduction ...
Page 10: ...Specification 2 6 Samsung Electronics Contents may change without notice ...
Page 16: ...Installation 3 6 Samsung Electronics Contents may change without notice ...
Page 22: ...4 6 Samsung Electronics Contents may change without notice NAM Programming ...
Page 52: ...Troubleshooting 7 8 Samsung Electronics Contents may change without notice 7 2 2 CDMA Mode ...
Page 54: ...Troubleshooting 7 10 Samsung Electronics Contents may change without notice ...
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Page 68: ...8 14 Samsung Electronics Contents may change without notice Exploded View and its Parts List ...
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Page 100: ...Electrical Parts List 10 24 Samsung Electronics Contents may change without notice ...
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Page 102: ...11 2 Rapid Desk Top Charger Block Diagram DTC58 ...
Page 103: ...11 3 Hands free Kit Block Diagram ...
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Page 105: ...11 4 Rapid Travel Charger Block Diagram ...
Page 106: ...11 5 CLA Cigarette Lighter Adaptor Block Diagram ...
Page 107: ...11 6 Logic Circuit Diagram ...
Page 108: ...11 7 Receiver Circuit Diagram ...
Page 109: ...11 8 Transmitter Circuit Diagram ...
Page 110: ...11 9 Desk Top Rapid Charger Circuit Diagram ...
Page 111: ...11 10 Hands Free Circuit Diagram ...
Page 112: ...11 10 1 Power Circuit Diagram ...
Page 113: ...11 10 2 Holder Circuit Diagram ...
Page 114: ...11 10 3 COMM CONT Circuit Diagram ...
Page 115: ...11 10 4 Audio Amp Circuit Diagram ...
Page 116: ...11 11 Cradle Circuit Diagram ...
Page 117: ...11 12 Car Adaptor Circuit Diagram ...
Page 118: ...11 13 Rapid Trvel Charger Circuit Diagram ...
Page 119: ...11 14 CLA Cigarette Lighter Adaptor Circuit Diagram ...