HUAWEI MC509 Series CDMA LGA Module
Hardware Guide
Description of the Application Interfaces
Issue 02 (2013-05-06)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
23
Table 3-2 lists the definitions of the pins on the power supply interface.
Table 3-2
Definitions of the pins on the power supply interface
Pin No.
Signal
Name
I/O
Description
DC Characteristics (V)
Min. Typ.
Max.
12, 13
VBAT
P
Pins for power voltage input
3.3
3.8
4.2
48, 49, 50, 52, 53,
54, 56, 57, 58, 59,
106, 108, 110, 112,
114, 116
GND
-
GND
-
-
-
32
VCC_EXT1 P
Pin for external power output -
1.8
-
31
VCC_EXT2 P
Pin for external power output -
2.6
-
34
RUIM_VCC P
Power supply for RUIM card
-
1.8/2.85
-
121
–145
GND
-
Thermal Ground Pad
-
-
-
3.3.2
VBAT Interface
When the MC509 module works normally, power is supplied through the VBAT pins
and the voltage ranges from 3.3 V to 4.2 V (typical value: 3.8 V). The 145-pin LGA
provides two VBAT pins and GND pins for external power input. To ensure that the
MC509 module works normally, all the pins must be used efficiently.
When the MC509 module is used for different external applications, pay special
attention to the design for the power supply. When the MC509 module transmits
signals at the maximum power, the transient current may reach the transient peak
value of about 1.5 A due to the differences in actual network environments. In this
case, the VBAT voltage drops. Make sure that the voltage does not decrease below
3.3 V in any case. Otherwise, exceptions such as restart of the MC509 module may
occur.
A low-dropout (LDO) regulator or switch power with current output of more than 1.5 A
is recommended for external power supply. Furthermore, a 220 µF or above energy
storage capacitor is connected in parallel at the power interface of the MC509
module.
It is recommended that add the EMI ferrite bead (NR3015T4R7M manufactured by
TAIYO YUDEN or VLS3015T-4R7MR99 manufactured by TDK is recommended) to
directly isolate DTE from DCE in the power circuit. Figure 3-2 shows the
recommended power circuit of MC509 module.
