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GT-1612-MTBD
GPS&Beidou Receiver Module
www.gotop-zzu.com
Page 20 of 35
Revision: V2.0.1-January 2015
2.10. PPS VS. NMEA
Figure 12:
PPS VS. NMEA Timing
This feature only supports 1Hz NMEA output and baud rate at 14400~115200bps. At baud rate of 9600 and
4800bps, it only supports RMC NMEA sentence. Because at low baud rate, per second transmission may exceed one
second if there are many NMEA sentences output. You can enable this function by sending “$PMTK255,1*2D”, and
disable the function by sending “$PMTK255,0*2C”.
3 Antenna Interfaces
3.1. PCB Design Guide
The GT-1612-MTBD GPS&Beidou receiver is designed for supporting the active antenna or passive antenna
connected with pin RF_IN. The gain of active antenna should be no less than 15dB. The maximum noise figure should
be no more than 2.5dB and output impedance is at 50 Ohm.
Figure 13:
Antenna design requirements