HUAWEI EM820W HSPA+ PC Embedded Module
Hardware Guide
Description of the Application Interfaces
Issue 01 (2010-12-09)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
8
Definition of the EM820W Mini PCI Express pins
Pin
No.
Mini PCI
Express
Standard
Description
HUAWEI Pin
Description
Additional
Description
Direction to
Module
50
GND
GND
Mini Card Ground.
-
51
Reserved
NC
Not connected.
-
52
3.3Vaux VCC_3V3 3.3V DC supply rail
from the PC side.
Input
3.3 Power Sources and Grounds
The PCI Express Mini Card provides two power sources: one is 3.3 Vaux (+3.3 Vaux)
and the other is 1.5 V (+ 1.5 V). For the EM820W, however,
+3.3
Vaux
is the only
voltage supply that is available. The input voltage is 3.3 V±9%, as specified by
PCI
Express Mini CEM Specifications 1.2
.
Table 3-2
Power and ground specifications
Name
Pins
Minimum Type
Maximum
VCC
2, 24,39, 41, and 52
3.0 V
3.3 V
3.6 V
GND
4, 9, 15, 18, 21, 26, 27, 29, 34,
35, 37, 40, 43, and 50
0 V
To minimize the RF radiation through the power lines, it is suggested to add ceramic capacitors
of 10pF and 100nF in the ground beside the Mini PCI Express connector on the host side.
3.4 Power Supply Time Sequence
Figure 3-1 shows the PCIE with 3.3 V voltage and USB D+ power supply time
sequence.
