User's Manual

MeiG hardware design guide
4
4. Interface Application
4.1 Power Supply
In the case of a battery device, the voltage input range of the module VBAT is 3.4V to 4.2V, and
the recommended voltage is 3.8V. In the LTE band, when the module is transmitting at maximum
power, the peak current can reach up to 3A, resulting in a large voltage drop on VBAT.
It is recommended to use a large capacitor regulator close to VBAT. It is recommended to use
two 47uF ceramic capacitors. Parallel 33PF and 10PF capacitors can effectively remove high
frequency interference. To prevent damage to the chip due to ESD and surge, it is recommended to
use a suitable TVS tube and a 5.6V/500mW Zener diode at the VBAT pin of the module. For PCB
layout, the capacitors and diodes should be as close as possible to the VBAT pin of the module. The
user can directly power the module with a 3.7V lithium-ion battery. When using the battery, the
impedance between the VBAT pin and the battery should be less than 150mΩ.
Figure 4.1：VBAT input reference circuit
If it is a DC power supply device, the DC input voltage is 5V-12V, and the recommended circuit
that can be powered by DC-DC is shown below.