U)Sim Interface - Quectel EC21 Series Hardware Design

NOTE
1. Use RESET_N only when failed to turn off the module by AT+QPOWD and PWRKEY pin.
2. Ensure that there is no large capacitance on PWRKEY and RESET_N pins.

3.9. (U)SIM Interface

The (U)SIM interface circuitry meets ETSI and IMT-2000 requirements. Both 1.8 V and 3.0 V (U)SIM
cards are supported.
Table 10: Pin Definition of (U)SIM Interface
Pin Name Pin No.
USIM_VDD 14
USIM_DATA 15
USIM_CLK 16
USIM_RST 17
USIM_
13
PRESENCE
EC21_Series_Hardware_Design
Figure 16: Reset Timing
I/O Description
PO (U)SIM card power supply
DIO (U)SIM card data
DO (U)SIM card clock
DO (U)SIM card reset
DI (U)SIM card insertion detect
LTE Standard Module Series
Comment
Either 1.8 V or 3.0 V is
supported by the module
automatically.
1.8 V power domain.
If unused, keep it open.
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