SIM28 GPS Receiver Modem designed based on SIMCOM’s SIM28M/SIM28ML GPS Module. SIM28M is a stand-alone or A-GPS receiver. SIM28M consists of an inbuilt LNA, which can relax antenna requirement and eliminates the need for external LNA. Even without network assistance SIM28, can track as low as -165dBm signal. SIM28M features excellent low power consumption characteristics (acquisition 17mA, tracking 16mA). SIM28M is capable of supporting various location and navigation applications, including autonomous GPS, QZSS, SBAS ranging (WASS, EGNOS, GAGAN, MSAS), DGPS, and A-GPS. Moreover, the inbuilt antenna circuitry in this modem is capable of receiving signals even at difficult locations where other modem fails to receive signal. Use an external antenna of 1575.42MHz.
This GPS smart receiver consists of 16 channels with Ultra-low-power GPS architecture. This SIM28 GPS Receiver Modem features high position, velocity, and time accuracy performances. As well as high sensitivity and tracking capabilities. The modem powered using 9~15V DC (DC Only) Adaptor connected to DC Jack/Socket J1. The modem protected from reverse polarity using a diode.
SIM28 GPS Receiver Modem operates on +3.3V supply, 9~15V which is fed to the input of 78M05 voltage regulator IC. Thus the output from 78M05 IC of +5V provided as input to LM1117 IC which in turn gives +3.3V output to SIM28M IC. SIM28 GPS Receiver Modem supports TTL Interface. So that the user can directly use TTL output available at connector J3. A level shifter is used to make the module compatible with +5V,+3.3V & 2.8V microcontrollers.