9
UM220 -IV M0
RF_IN
VCC_RF
Figure 4-1 UM220-IV M0 Active A3V Solution
If the UM220-IV M0 uses an active antenna other than +3V, the bias voltage required by
the antenna V_BIAS is supplied to the antenna through a feed inductor.
V_BIAS
UM220 -IV M0
RF_IN
VCC_RF
Figure 4-2 UM220-IV M0 Active Antenna (Other than +3v) Solution
If UM220-IV M0 uses passive antenna, the antenna is directly connected to RF_IN pin,
while VCC_RF can be suspended. It should be noted that the use of passive antennas
may cause a decrease in GNSS performance compared to active antennas.
UM220 -IV M0
RF_IN
VCC_RF
Figure 4-3 UM220-IV M0 Passive Antenna Solution
4.4
Serial Port
UM220-IV M0
has one LVTTL serial port, for PC connection, please use a RS232 voltage
level converter.
