Power Sources And Grounds; Power Supply Time Sequence; Table 3-2 Power And Ground Specifications - Huawei EM820W Hardware Manual

HUAWEI EM820W HSPA+ PC Embedded Module
Hardware Guide
Definition of the EM820W Mini PCI Express pins
Pin
No.
50
51
52

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
VCC
GND

3.4 Power Supply Time Sequence

Figure 3-1 shows the PCIE with 3.3 V voltage and USB D+ power supply time
sequence.
Issue 01 (2010-12-09)
Mini PCI
Express
Standard
Description
GND
Reserved
3.3Vaux
Pins
2, 24,39, 41, and 52
4, 9, 15, 18, 21, 26, 27, 29, 34,
35, 37, 40, 43, and 50
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.
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Copyright © Huawei Technologies Co., Ltd.
Description of the Application Interfaces
HUAWEI Pin Additional
Description Description
GND Mini Card Ground.
NC
Not connected.
VCC_3V3 3.3V DC supply rail
from the PC side.
Minimum
3.0 V
0 V
Direction to
Module
-
-
Input
Type Maximum
3.3 V 3.6 V
8