U)Sim Design Notices; Usb Interface - Quectel EM05-G Hardware Design

4.1.6. (U)SIM Design Notices

To enhance the reliability and availability of the (U)SIM card in applications, please follow the criteria
below in (U)SIM circuit design.
Place the (U)SIM card connector as close to the module as possible. Keep the trace length less than
⚫
200 mm.
⚫ Keep (U)SIM card signals away from RF and VCC traces.
⚫ To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and
shield them with surrounded ground.
⚫ To offer better ESD protection, add a TVS diode array of which the parasitic capacitance should be
not higher than 10 pF. Add 22 Ω resistors in series between the module and the (U)SIM card
connector to suppress EMI such as spurious transmission, and to enhance ESD protection. The
33 pF capacitors are used to filter out RF interference.
⚫ For USIM_DATA, a 10–20 kΩ pull-up resistor must be added near the (U)SIM card connector.

4.2. USB Interface

EM05-G is compliant with USB 2.0 specification. It can only be used as a slave device. Meanwhile, it
supports high speed (480 Mbps) and full speed (12 Mbps) mode. The USB interface is used for AT
command communication, data transmission, GNSS NMEA output, software debugging and firmware
upgrade. The following figure shows the reference circuit of USB interface.
Please note that only USB 2.0 can be used for firmware upgrade currently.
The following table shows the pin definition of USB interface.
Table 11: Pin Definition of USB Interface
Pin No. Pin Name
7 USB_DP
9 USB_DM
For more details about the USB 2.0 specifications, visit http://www.usb.org/home.
EM05-G_Hardware_Design
I/O Description
AIO USB 2.0 differential data (+)
AIO USB 2.0 differential data (-)
LTE Standard Module Series
EM05-G Hardware Design
Comment
Requires differential
impedance of 90 Ω
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