MIMXRT1060-EVKB: Power input for SD-Card

[Sam_ECU]

Hello,

I'm trying to understand the SD-Card layout for the MIMXRT1060-EVKB.

In the schematic there is a card detection switch, SD_CD_SW which is wired to the input "GPIO_B1_12 / D13" (USDHC1_CD_B), but the Gate of the Mosfet for "VSD_3V3", SD_PWREN is connected to "GPIO_AD_B1_03/ M12" (USDHC2_CD_B).

Why has it been designed this way, that the card detection from module 2 drives the power input for the SD-Card running on module 1?

Could SD_CD_SW from module 1 not be the gate for the power input mosfet?

(Also, should the DNP Capacitors and Resistors be used?  Why are they DNP?)

Thanks for the insight.

Regards,

Sam

Sam_ECU_0-1667119981831.pngSam_ECU_1-1667120017021.png

[Hui_Ma]

Hi

SD_PWREN function to control SD card slot power, which was a GPIO output pin, customer can select other GPIO pin, not fixed to "GPIO_AD_B1_03/ M12".

Due to RT1060 supports boot from SD card, there should keep SD_CD_SW pin low during SD boot.

Could SD_CD_SW from module 1 not be the gate for the power input mosfet?

I do not understand this question, current design is not using SD_CD_SW. If you want to know if you can use the SD_CD_SW as gate for the power input MOSFET. The answer is yes.

MIMXRT1060-EVKB is an evaluation design for using most RT1060 module and also provide flexiblity to do some power consumption measurement. Sush as R223 was DNP for SD card power consumption measurement.

Thanks for the attention.

Mike