Quectel LPWA Series Hardware Design

LPWA Module Series
BG950A-GL&BG951A-GL_Hardware_Design
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To enhance the reliability and availability of the (U)SIM card in applications, please follow the criteria
below in the (U)SIM circuit design:

Keep the placement of (U)SIM card connector as close to the module as possible.
 Keep the trace length as less than 200 mm as possible.

Keep (U)SIM card signals away from RF and VBAT traces.
 Assure the ground between the module and the (U)SIM card connector short and wide. Keep the
trace width of ground and USIM_VDD no less than 0.5 mm to maintain the same electric potential. If
the ground is complete on customers’ PCB, USIM_GND can be connected to PCB ground directly.

Make sure the bypass capacitor between USIM_VDD and USIM_GND less than 1 μF, and place it
as close to (U)SIM card connector as possible.
 To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and
shield them with surrounded ground.

To offer good ESD protection, it is recommended to add a TVS diode array of which parasitic
capacitance should not be more than 15 pF. The 0 Ω resistors should be added in series between
the module and the (U)SIM card to facilitate debugging. The 33 pF capacitors are used for filtering
interference of EGSM900. Please note that the (U)SIM peripheral circuit should be close to the
(U)SIM card connector.
 The pull-up resistor on USIM_DATA trace can improve anti-jamming capability when long layout
trace and sensitive occasions are applied, and should be placed close to the (U)SIM card
connector.
4.2. USB Interface*
The module provides one USB interface. The USB interface complies with the USB 2.0 specifications,
and supports Full-speed (12 Mbps) and Low-speed (1.5 Mbps) for USB 2.0.
USB interface is used AT command communication, data transmission, software debugging and firmware
upgrade.
Table 13: Pin Definition of USB Interface
Pin Name
Pin No.
I/O
Description
Comment
USB_VBUS
8
AI
USB connection detect
Typ. 5.0 V
USB_DP
9
AIO
USB differential data (+)
Compliant with USB 2.0
standard specification. Require
differential impedance of 90 Ω.
USB_DM
10
AIO
USB differential data (-)

Quectel LPWA Series Specifications

General

Brand	Quectel
Model	LPWA Series
Category	GSM/GPRS Modules
Language	English