AnsweredAssumed Answered

SD Power Enable

Question asked by Heath Pritchett on Jan 15, 2020
Latest reply on Jan 21, 2020 by Jing Pan



I have a custom board based off of the RT1064-EVK. I am having issues resetting the SD card VDD using M12 GPIO_AD_B1_03 and a simple p-channel mosfet in a high side switch configuration. I have tested this circuit with a restive load at around 300mA with the SD card removed and it works fine. However, when the SD card is inserted and I pull M12 low I measure about 2.3V DC. It seems that there is some leakage current from the SD card IO pins back on VDD. I have compared this to the EVK which does not show this error(unless the SD data lines are driven high then I do, but not in the SD driver demo example). Is there anything I am missing? Why can I not drive VDD low?