Huawei MG323 manual VBAT Interface, Module, Pin No, Signal Name, Description

HUAWEI MG323 GSM M2M Module
Hardware Guide			Description of the Application Interfaces
Table 3-2Definitions of the pins on the power supply interface
	Pin No.	Signal Name	I/O	Description
	42, 44, 46, 48, 50	VBAT	P	Pins for Power supply input
	41, 43, 45, 47, 49	GND	-	GND
	35	VCOIN	P	Pin for standby power input of
				the RTC
	40	VIO	P	Pin for external power output

3.3.2VBAT Interface

When the MG323 module works normally, power is supplied through the VBAT pins and the voltage ranges from 3.3 V to 4.8 V (typical value: 3.8 V). The 50-pin B2B connector provides five VBAT pins and five GND pins for external power input. To ensure that the MG323 module works normally, all the pins must be used efficiently.

When the MG323 module is used for different external applications, pay special attention to the design for the power supply. When the MG323 module transmits signals at the maximum power, the transient current may reach the transient peak value of about 2.0 A due to the differences in actual network environments. In this case, the VBAT voltage greatly drops. Make sure that the voltage does not decrease below 3.3 V in any case. Otherwise, exceptions such as restart of the MG323 module may occur.

A low-dropout (LDO) regulator or switch power with current output of more than 2 A is recommended for external power supply. Furthermore, At least five 220 µF storage capacitors should be connected in parallel at the power interface of the MG323 module. In addition, to reduce the impact of channel impedance on voltage drop, you are recommended to try to shorten the power supply circuit of the VBAT interface.

It is recommended to employ a ferrite bead in series on VBAT power circuit to improve the EMI performance. And the rated current of the ferrite bead is required at least 2 A.

Figure 3-2shows the recommended power circuit of MG323 module.

Figure 3-2Recommended power circuit of MG323 module

Module

(DCE)

VBAT

10 μF 100 nF

VBAT

+ + + + +

220 μF 220 μF 220 μF 220 μF 220 μF

Issue 06 (2013-06-13)	Huawei Proprietary and Confidential	17
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