The local oscillator (LO1) consists of a PLL inside the Smarti DC (D720), an external loop
filter. The VCO is build in.
The first local oscillator is needed to generate frequencies which enables the transceiver IC
to demodulate the receiver signal and to perform the channel selection in the TX part. The
LO1/PLL part is switched on with
) from the
(GSM TDMA Timer
). The PLL settings are programmed by the 3 wire bus
). The LO frequency is 4 times the RX/TX frequency for EGSM 900 and 2
times for GSM1800.
This LO1 frequency range
The required voltage
is provided by the
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ICM MP CCQ GRM
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