Product Info

LTE Module Series
EC21 Hardware Design
EC21_Hardware_Design
3-41
/ 105
high level detections, and is disabled by default. Please refer to document [2] about AT+QSIMDET
command for details.
The following figure shows a reference design for (U)SIM interface with an 8-pin (U)SIM card connector.
Figure 17: Reference Circuit of (U)SIM Interface with an 8-Pin (U)SIM Card Connector
If (U)SIM card detection function is not needed, please keep USIM_PRESENCE unconnected. A
reference circuit for (U)SIM interface with a 6-pin (U)SIM card connector is illustrated in the following
figure.
Figure 18: Reference Circuit of (U)SIM Interface with a 6-Pin (U)SIM Card Connector
In order to enhance the reliability and availability of the (U)SIM card in customers’ applications, please