Jackson Labs LTE-Lite, User Manual

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LTE-Lite User Manual
which then allows feeding an external 3.3V CMOS or TTL RF signal into the RF pin 6 of the
module. The former RF output pin 6 of the module becomes an RF input pin when pulling pin 8 of
the module high. The module TCXO Disable pin 8 is pulled-low internally to the module to allow the
internal TCXO to operate by default. Allowable external frequencies are 10MHz, 15.36MHz,
19.2MHz and 20MHz. Additional frequencies may be supported by the firmware at a later date.
External oscillators can be disciplined directly by the modules’ EFC output pin 1, and should have
50K Ohms or higher resistance to ground on their EFC pins. The EFC output pin 1 has a voltage
range of 0V to 3.0V an requires external oscillators with positive frequency slope.
Figure 2.10 Connecting an external TCXO to the LTE-Lite SMT Module