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impedance to connect RF_IN to the antenna or any antenna connectors that you prefer. 
(Impedance 50Ω) 

(5) FM_RF_IN: 

Connecting to the antenna has to be routed on the PCB.

 

The transmission line must control 

impedance to connect FM_RF_IN to the antenna or any antenna connectors that you prefer. 
(Impedance 50Ω) 

(6) Power: 

Connect V_GPS_3V3 and V_TMC_3V3 pin to DC 3.3V. The power supply must add a 
bypassing capacitor (10uF and 1uF) to reduce the noise from power supply and increase 
power stability. 

(7)  Active antenna bias voltage: 

The Vcc_RF_OUT pin (pin 20) provides voltage 2.85V. If you use an active antenna, you 
can connect this pin to V_ANT_IN pin (pin 19) for providing bias voltage of an active 
antenna. The bias voltage will run through GPS_RF_IN pin to provide active antenna bias 
voltage from Vcc_RF_OUT pin. 
If your bias voltage of an active antenna isn’t 2.85V, you can input bias voltage that you 
need to V_ANT_IN pin (pin 19). The input bias voltage will run through GPS_RF_IN pin 
to provide active antenna bias voltage from V_ANT_IN pin. 
PS: 
(Ⅰ). The maximum power consumption of active antenna is around 85mW. 
(Ⅱ). The input gain ranges from 12 to 26dB. 

(8) GPIO: 

The GPIO pin is recommended to connect to serial resistance(220Ω), if the GPIO function 

is used. 
If GPIO function is not used, it won’t connect anything.