UNICORECOMM UM220-IV M0, User Manual

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UM220-IV M0 User Manual
8
No Name I/O Electrical level Description
1 GND I Ground
2 TXD O LVTTL UART 1-TX
3 RXD I LVTTL UART 1-RX
4 TIMEPULSE O LVTTL 1PPS
5 NC I LVTTL Reserve
6 V_BCKP I 1.4V~3.6V Voltage for RTC
7 VCC_IO I 2.8V~3.6V GPIO power supply
8 VCC I 2.8V~3.6V Main power
9 nRESET I LVTTL
For reset, Low level active, if you do not
use the pin, please leave it hanging
10 GND I Ground
11 RF_IN I GNSS signal input (BDS B1+GPS L1
）
12 GND I Ground
13 NC O Reserve
14 VCC_RF 3 O =VCC Output voltage RF section
15 NC I/O Reserve
16 NC I/O Reserve
17 NC I/O Reserve
18 NC I/O Reserve
4 Hardware Design
4.1 Design in Considerations
To make UM220-IV M0 work normally, you need to properly connect the following :
The Module VCC has good monotonicity. If the VCC power off and then on, the power
off time must be more than 10ms.
 It is recommended that a 1KΩ resistance should be connected in series to RX, a
33Ω or 1 KΩ resistance should be connected in series to TX, and a 4.7K resistor
should be connected in series to other necessary PIO in the Pin .

Connect all the GND pins to ground.

Connect the RF_IN signal to the antenna, and the line will keep 50Ω impedance
3 VCC_RF does not have short circuit detection function;