HUAWEI MU739 HSPA+ LGA Module
Hardware Guide
Description of the Application Interfaces
Issue 01 (2011-08-24)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
21
VBAT_PA voltage droops. Make sure that the voltage does not decrease below 3.3 V
in any case. Otherwise, exceptions such as reset of the MU739 module may occur.
A low-dropout (LDO) regulator or switch-mode power supply with load current larger
than 2 A is recommended. At least three 220 µF capacitors should be installed to
VBAT_PA pins. And the trace of the power supply should be as short and wide as
possible.
It is recommended to employ a ferrite bead in series on VBAT to improve the EMI
performance.
FC FBMJ1608HS280NT manufactured by TAIYO YUDEN or MPZ1608S300ATAH0
manufactured by TDK is recommended.
Figure 3-2 shows the recommended power circuit of MU739 module.
Figure 3-2
Recommended power circuit of MU739 module
3.3.3
Output Power Supply Interface
Output power supply Interfaces are SIM_VCC, VCC_EXT1. Through the SIM_VCC
power supply interface, the MU739 module can supply 1.8 V and 2.9 V power
externally with an output current of 70 mA (typical value).The VCC_EXT1 pin can
supply 1.8 V power.
3.4 Signal Control Interface
3.4.1
Overview
The signal control part of the interface in the MU739 module consists of the following:
Power on (ON1, ON2_N) pins
Reset output pin (RESOUT_N)
System reset pin
(
PWRDWN_N
)
Module
(Modem)
VBAT_PA
VBAT
22
μ
F
+
+
+
220
μ
F
220
μ
F
220
μ
F
1
μ
F
100 nF
330 pF
VBAT_PMU
VBAT
22
μ
F
1
μ
F
100 nF
330 pF
Ferrite bead
Ferrite bead
draft2