Quectel EG91 Series Hardware Design page 44

Figure 17: Reference Circuitof (U)SIMInterface with an 8-Pin (U)SIMCard Connector
If (U)SIM card detection function is not needed, please keep USIM_PRESENCE unconnected.
Areference circuit of (U)SIM interface with a 6-pin (U)SIMcard connector is illustrated inthe following
figure.
Figure 18: Reference Circuitof (U)SIM Interface with a 6-Pin (U)SIM Card Connector
In order to enhance the reliability and availability of the (U)SIM cardin customers' applications, please
follow the criteria below in the (U)SIMcircuit design:
 Keep placementof (U)SIMcard connector to the module as close as possible. Keep the trace length
as less than 200mm as possible.
Keep (U)SIMcard signals away from RF and VBAT traces.

EG91_Hardware_Design 43 / 93
LTE Module Series
EG91 Hardware Design