GT-1612-MTBD
GPS&Beidou Receiver Module
www.gotop-zzu.com
Page 7 of 35
Revision: V2.0.1-January 2015
2.3. Power Supply
VCC pin supplies power for BB, RF, I/O, LNA, short protection and antenna detection circuit. The load current of
VCC varies according to the VCC level, processor load, the number of tracked satellites and the rate of satellite
re-acquisition. Using external active antenna will consume additional 11mA from our module. So it is important to
supply sufficient current and make the power clean and stable. VCC supply ripple voltage should meet the
requirement: 54mV (RMS) max @f=0
…
3MHz and 15mV (RMS) max@f >3MHz. You should choose the LDO
without built-in output high-speed discharge function to keep long output voltage drop-down period. The decouple
combination of 10uF and 100nF capacitor is recommended nearby VCC pin.
UART Port
Pin Name
Pin No.
I/O Description
DC Characteristics
Comment
RXD
21
I
Receive data
VILmin=-0.3V
VILmax=0.8V
VIHmin=2.0V
VIHmax=3.6V
TXD
20
O
Transmit data
VOLmin=-0.3V
VOLmax=0.4V
VOHmin=2.4V
VOHmax=3.1V
RF Interface
Pin Name
Pin No.
I/O Description
DC Characteristics
Comment
RF_IN
11
I
External active
antenna RF input
Characteristic impedance of
50Ω
VCC_RF
9
O
Active antenna
power output
Vnom=3.3V
Output Voltage RF section.
VCC_RF can be selected
according to the type of
antenna.
Other Interfaces
Pin Name
Pin No.
I/O Description
DC Characteristics
Comment
PPS
3
O
One pulse
per second
VOLmin=-0.3V
VOLmax=0.4V
VOHmin=2.4V
VOHmax=3.1V
Synchronized at rising
edge, the pulse width
is100ms. If unused, keep
this pin open.
