HUAWEI ME909s Series LTE Mini PCIe Module
Hardware Guide
Description of the Application Interfaces
Issue 02 (2016-09-07)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
29
It is recommended that you wrap the area adjacent to the USIM_CLK and
USIM_DATA signal wires with ground. The Ground pin of the USIM socket and the
Ground pin of the USIM card must be well connected to the power Ground pin
supplying power to the PCIe Adapter.
A 33 pF capacitor and1
μF capacitor are placed between the USIM_PWR and
Ground pins in a parallel manner (If USIM_PWR circuit is too long, that the larger
capacitance such as 4.7
μF can be employed if necessary). Three 33 pF
capacitors are placed between the USIM_DATA and Ground pins, the
USIM_RESET and Ground pins, and the USIM_CLK and Ground pins in parallel to
filter interference from RF signals.
It is recommended to take electrostatic discharge (ESD) protection measures near
the USIM card socket. The TVS diode with Vrwm of 5 V and junction capacitance
less than 10 pF must be placed as close as possible to the USIM socket, and the
Ground pin of the ESD protection component is well connected to the power
Ground pin that supplies power to the PCIe Adapter.
It is not recommended that pull the USIM
_DATA pin up during design as a 15000 Ω
resistor is used to connect the USIM_DATA pin to the USIM_PWR.
It is recommended to place a 1
kΩ
resistor in series on the USIM_DET interface for
ESD protection if USIM_DET is used.
3.8 Audio Interface
The ME909s Mini PCIe module provides one PCM digital audio interface. Table 3-9
lists the signals on the digital audio interface.
Table 3-9
Signals on the digital audio interface
Pin
No.
Pin Name
Pad
Type
Description
Parameter
Min.(V)
Typ.(V)
Max.(V)
45
PCM_CLK
O
PCM interface clock
V
OL
–0.3
0
0.45
V
OH
1.35
1.8
1.98
47
PCM_DOUT
O
PCM I/F data output V
OL
–0.3
0
0.45
V
OH
1.35
1.8
1.98
49
PCM_DIN
I
PCM I/F data input
V
IL
–0.3
0
0.63
V
IH
1.17
1.8
1.98
51
PCM_SYNC
O
PCM interface sync
V
OL
–0.3
0
0.45
V
OH
1.35
1.8
1.98
The ME909s Mini PCIe module interface enables communication with an external
codec to support linear format.