nrf9160 hardware

[Mac-fang]

嗨，

 我正在测试NRF9160，但找不到SIM卡。而且我发现SIM_1V8的引脚为低。我怎样才能打开它？它由3V3供电。

[Mac-fang]

Hi ,

   yes. Thanks for your reply.  it's custom board .  But i don't have  nRF9160-DK,so i can't test with it now.

   i have another question, is there a pin used for controling the output of SIM_1V8 .Actually some 4G modules have this pin . And there are two buttons in DK for nRF9160 , what are they used for ? 

[Amanda Hsieh]

Hi, 

Are you able to get 1.8 volt in the sim slot?

Mac-fang said:

is there a pin used for controling the output of SIM_1V8 .Actually some 4G modules have this pin .

What does the pin control the output of SIM_1V8 for? Is it for SIM and eSIM as nRF9160-DK?

Mac-fang said:

And there are two buttons in DK for nRF9160 , what are they used for ? 

 Button 1 and Button 2 are for the user's application. See Buttons, slide switches, and LEDs.

-Amanda H.

[Mac-fang]

Hi 

  I had checked the DK board. It can provide SIM 1.8V when put the SIM inside. So  how is it working ? 

 Could you  help me check the design ? Thanks,  i think something are missed.

OCL-0001.sch.pdf

[JONATHAN LL]

Hi,


the SIM_DET should be left open/floating,





Try to remove R2 and see if it it is detected.


Regards,
Jonathan

[Mac-fang]

Hi ,

   I had tried. But it seems can't make sense.

[JONATHAN LL]

Hi,

Information regarding SIM interface:
https://infocenter.nordicsemi.com/topic/nwp_034/WP/nwp_034/nwp_034_uicc_interface.html?cp=2_0_7_1_2_3 

https://infocenter.nordicsemi.com/topic/nwp_037/WP/nwp_037/uicc_if.html?cp=2_0_7_0_3_9


https://infocenter.nordicsemi.com/topic/nwp_037/WP/nwp_037/uicc_if_esd.html?cp=2_0_7_0_3_9_0 


https://infocenter.nordicsemi.com/topic/nwp_037/WP/nwp_037/uicc_if_pcb.html?cp=2_0_7_0_3_9_1 


ESD filtering is recommended, see ref design:


It is possible to use discrete components to filter.

Discrete ESD protection can consist of the following components:
• Bypass capacitors in the range of ≤ 22 pF to SIM_RST, SIM_DET, SIM_CLK, SIM_IO, and SIM_1V8.
    • A separate supply capacitor ranging from 100 nF to 220 nF connected to SIM_1V8 can be considered.

• Low capacitance type ESD diodes to SIM_RST, SIM_DET, SIM_CLK, SIM_IO, and SIM_1V8.
    • Multichannel ESD diodes are commonly used and recommended.
    • Some multichannel diode components incorporate EMI filtering. This type is recommended if the product integrates an LTE antenna or an external antenna is located close to the SIM holder.


Is the SIM holder placed close to any RF components?



If you want you can share the PCB files and i can look at the layout. If you dont want the PCB files to be public then you can make a new private ticket or we can make this ticket private.


Can you cut\disconnect SIM_DET ?


R4, R5 and R22 should not be there or changed to 0 Ohm, the impedance should be as low as possible. 

Can you share what nano-SIM card holder you are using ?

Regards,
Jonathan