Specifications

SIM7028 Hardware Design V1.00
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3 Interface Application
3.1 Power Supply
Pin 34 and pin 35 are VBAT power input.
The power supply for SIM7028 must be able to provide sufficient current up to more than 500mA in order to
satisfy the power supply current for maximum consumption.
The module can use an LDO with a low quiescent current output capability of 1 A as the power supply, or it
can be powered by a battery. When the module is working in the digital transmission mode, it must be
ensured that the power drop does not fall below the minimum working voltage of the module 2.2 V,
otherwise the module will be abnormal.
At the VBAT pin of the module, you can refer to the following devices, where CA is a low ESR 100
µ
F
tantalum capacitor. In addition, to prevent surges and static electricity, it is recommended to connect TVS in
parallel with the VBAT pin of the module. If you choose a Zener tube, please pay special attention to the
static power consumption of the Zener tube. During PCB layout, the capacitor and TVS should be as close
as possible to the VBAT pin of the module.
Figure 5: Power supply application circuit
3.2 Power on/Power off/Reset Function
3.2.1 Power on
The module is automatically turned on after power on, without a power button. Under the condition that the
RESET pin is not pulled low by the outside, the module will automatically power on after supplying a voltage