Sunsea AIoT SimCom SIM7090G User Manual page 35

SIM_DATA has been pulled up with a 20KΩ resistor to SIM_VDD in module, so it no need pulled up resistor
anymore. SIM_VDD needs a 100nF capacitor close to SIM socket.
SIM_CLK is very important signal, the rise time and fall time of SIM_CLK should be less than 40ns. So the
junction capacity of the TVS need to less 50pF.
In order to enhance the reliability and availability of the (U)SIM card in applications. Please follow the
guidelines below when designing.
It is recommended to place a 100nF capacitor on the SIM_VDD signal line close to the SIM card

holder.
Place TVS near the SIM card holder. The junction capacity of the TVS should not exceed 50pF.

The 22Ω resistor in series between the SIM card holder and the module can enhance the ESD
protection performance.
Keep SIM card signals away from RF and VBAT traces.

SIM card signal line traces to avoid branch.

To avoid cross-talk between SIM_DATA and SIM_CLK, keep them away from each other and

shield them with surrounded ground. USIM_RST should also be ground shielded.
3.6 PCM Interface
SIM7090G provides a PCM interface for external codec, which can be used in master mode with short sync
and 16 bits linear format.
www.simcom.com
Figure 16: SIM interface reference circuit
SIM7090G User Manual V1.01
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