Transceiver - Motorola V200 Service Manual

Level 3 Service Manual

Transceiver

6881039B10
USB and RS232 (3 wire) communications take place through the audio/power
controller IC. For V200 phones, USB mode is used for flashing. USB requires a
Motorola USB accessory cable to interface with a personal computer (PC). RS232
is used for testing, phasing, and flashing the phone. RS232 requires a Motorola
RS232 data head to interface to a PC.
In the V200 CE Bus pin 2 serves the dual functions of BATTFDBK and MANTST.
BATTFDBK is used for controlled power dissipation by the charger. MANTST is
used to detect the type of charger (Full rate, Mid rate, and Invalid). Initially, the
audio/power controller IC reads the voltage on this pin to determine the charger
type, then the BATTFDBK signal is active.
Detailed functional block diagrams, schematics, and parts lists for the transceiver
board are provided in the Supplement listed in Related Publications section of this
manual.
Receive CDMA Cellular 800 MHz (PCS 1900 MHz)
The communicator receives the RF signal from antenna connector J9001 or RF test
port J9000. The received RF signal is routed through diplexer FL53 to mono-block
duplex SAW filter FL51 (mono-block duplex ceramic filter FL50 for PCS 1900
MHz). The RF signal is then routed to the front-end (FE) IC U9917, which contains
LNAs providing three stages of gain to the received RF signal based on its strength,
and interstage filtering. U9917 also contains a mixer which down converts the
signal to an IF of 109.8 MHz. FE IC U9917 is controlled by the call processor IC
U1100 on the controller board via signals FEIC_G1, FEIC_G2, and MODE. The
local oscillator signal RX_LO_800 (RX_LO_PCS for PCS 1900 MHz) is 978 – 1004
MHz (2039-2100 MHz for PCS 1900 MHz). VCO module U626 is controlled by the
RF transceiver IC U700. The 109.8 MHz IF signal out of the mixer is routed through
IF filter FL150 into the RF transceiver IC U700 for mixing with the second LO,
filtering and demodulation. The received QPSK data is gain-controlled and convert-
ed to a digital baseband signal within RF transceiver IC U700. The baseband signal
October 04, 2001
Circuit Description
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