User's Guide

3.3 POWER ON THE MCU AND LORA TRANCEIVER
There are two ways to power on the MCU and Lora transceiver.
After feed in 3.3~5V DC battery power to the pin V_IN and
(1) place a magnet on Hall Switch-1 or
(2) pull up pin 3V3_EN_1 to VIH(2.5~4.2V).
When the MCU is powered on, the power output pin VCC_P3V3 will be activated as well.
Table 3-5 specifies the technical maximum ratings of above operations.
.
12
V_IN Hall Switch-1 3V3_EN_1 VCC_P3V3
0 w/o magnet 0 off
0 w/o magnet 1 off
0 with magnet 0 off
0 with magnet 1 off
1 w/o magnet 0 off
1 w/o magnet 1 on
1 with magnet 0 on
1 with magnet 1 on
Table 3-5 Technical maximum ratings
Table 3-6 Control logic of power supply to the module.
Pin Name Parameter Max Typical Min Unit
V_IN Input battery power supply 5 4.2 3.3 V
Hall Switch
High magnetic threshold operate point
±
1.5
±
3
±
4.8 mT
Low magnetic threshold release point
±
0.5
±
1.5
±
3 mT
3V3_EN_1 VIH 4.2 3.3 2.5 V
3V3_EN_1 VIL 1.35 0 0 V