SIM800H datasheet(20/73 Pages) SIMCOM

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4. Application Interface

4.1. Power Supply

The power supply range of SIM800H&SIM800L is from 3.4V to 4.4V.Recommended voltage is 4.0V.The

transmitting burst will cause voltage drop and the power supply must be able to provide sufficient current up to

2A. For the VBAT input, a bypass capacitor (low ESR) such as a 100 µF is strongly recommended.

Increase the 33pF and 10pF capacitors can effectively eliminate the high frequency interference. A

5.1V/500mW Zener diode is strongly recommended, the diode can prevent chip from damaging by the voltage

surge. These capacitors and Zener diode should be placed as close as possible to SIM800H&SIM800L VBAT

pins.

Figure 5: Reference circuit of the VBAT input

Table 6: Recommended zener diode

Vendor

Part number

Power(watts)

Packages

On semi

MMSZ5231BT1G

500mW

SOD123

Prisemi

PZ3D4V2H

500mW

SOD323

Vishay

MMSZ4689-V

500mW

SOD123

Crownpo

CDZ55C5V1SM

500mW

0805

The following figure is the reference design of +5V input power supply. The designed output for the power

supply is 4.1V, thus a linear regulator can be used.

Figure 6: Reference circuit of the LDO power supply

SIM800H&SIM800L_Hardware Design_V2.02

2015-07-27

SIM800H Datasheet(PDF) 20 Page - SIMCom