Product Info

LTE Standard Module Series
EG95 Series Hardware Design
EG95_Series_Hardware_Design
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close to (U)SIM card connector as possible. If the ground is complete on customers’ PCB, USIM_GND
can be connected to PCB ground directly.
• To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and shield
them with surrounded ground.
• In order to offer good ESD protection, it is recommended to add a TVS diode array whose 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 line can improve anti-jamming capability when long layout trace
and sensitive occasion are applied, and should be placed close to the (U)SIM card connector.
3.10. USB Interface
EG95 contains one integrated Universal Serial Bus (USB) interface which complies with the USB 2.0
specification and supports high-speed (480 Mbps) and full-speed (12 Mbps) modes. The USB interface
can only serves as a slave device and is used for AT command communication, data transmission, GNSS
NMEA sentences output, software debugging, firmware upgrade and voice over USB. The following table
shows the pin definition of USB interface.
Table 10: Pin Definition of USB Interface
Pin Name
Pin No.
I/O
Description
Comment
USB_DP
9
IO
USB differential data bus (+)
Require differential
impedance of 90 Ω.
USB_DM
10
IO
USB differential data bus (-)
Require differential
impedance of 90 Ω.
USB_VBUS
8
PI
USB connection detection
Typical: 5.0 V
GND
3
Ground
For more details about USB 2.0 specifications, please visit http://www.usb.org/home.
The USB interface is recommended to be reserved for firmware upgrade in customers’ design. The
following figure shows a reference circuit of USB interface.