LG F7100, Service Manual

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3. TECHNICAL BRIEF
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(2) BB Transmit Section
This section generates in-phase and quadrature BB modulated GMSK signals (BT = 0.3) in
accordance with GSM 05.05 Phase 2 specifications.
The transmit channel consists of a digital GMSK modulator, a matched pair of 10-bit
DACs and a matched pair of reconstruction filter.
There are TXIP, TXIN, TXQP, TXQN, and RAMPDAC.
(3) BB Receiver Section
This section consists of two identical ADC channels that process baseband in-phase(I) and
quadrature(Q) input signals.
Each channel consists of a coarse switched capacitor input filter, followed by a high-order sigma-delta
modulator and a lowpass digital filter.
There are RXIP, RXIN, RXQP, and RXQN.
(4) Auxiliary Section
This section contains two auxiliary DACs(AFC DAC, IDAC) for system control.
This section also contains AUX ADC and Voltage Reference
AUX ADC : 6 channel 10 bits
AFC DAC : 13 bits
IDAC : 10 bits
(5) Voiceband Section
Receive audio signal from MIC. Send audio signal to Receiver. The phones use differential
configuration. It interconnects external devices such as main microphone, main receiver, ear-phone
through the VINNORP, VINNORN, VOUTNORP, VOUTNORN, VINAUXP, VINAUXN, VOUTAUXP,
and VOUTAUXN
VINNORP, VINNORN
: Main MIC positive/negative terminal.
VOUTNORP, VOUTNORN
: Main Receiver positive/negative terminal.
VINAUXP, VINAUXN
: ear-phone microphone positive/negative terminal.
VOUTAUXP, VOUTAUXON
: ear-phone speaker positive/negative terminal.