topic Re: Is the pin HIGH-Z status while IMX6D power off? in i.MX Processors

Is the pin HIGH-Z status while IMX6D power off?

翔李 — Thu, 24 May 2018 03:41:04 GMT

HI,

My board has IMX6D and st-MCU,sometimes to reduce power consumption of board,the MCU can power off the IMX6D,but,when power off IMX6D,the current of board is 12V@0.05A,I found that while I depopulate R1214, it change to 12V@0.01A,why? In my opinion,while power off the IMX6D,the pin of IMX6D is hi-Z states,why the TXD pin still consume current? and what about other IOs,for example,IIC,GPIO,UART,CAN and so on.

R1214 connect to CPU UART PIN=E24，UART2_TXD(EIM_D26).

Re: Is the pin HIGH-Z status while IMX6D power off?

Yuri — Thu, 24 May 2018 05:58:24 GMT

Hello,

The i.MX6 Datasheets - in Power Supplies Usage section - provide the following requirment:

"All I/O pins must not be externally driven while the I/O power supply for the pin (NVCC_xxx) is OFF.

This can cause internal latch-up and malfunctions due to reverse current flows".

This means, that i.MX6 cannot be considered as HIGH-Z, when the device is powered off.

Have a great day,

Yuri

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Re: Is the pin HIGH-Z status while IMX6D power off?

Yuri — Thu, 24 May 2018 06:08:11 GMT

> Please show me the IMX6 datasheet,I like to read chapter of Power Supplies Usage section.
> If I change the R1214 from 0R to 1K,it turn to 0.01A 12V.So,is it a good way to solve this problem?

Changing R1214 decrease leakage, but strictly speaking, a switch instead of R1214 should be applied.

Re: Is the pin HIGH-Z status while IMX6D power off?

翔李 — Thu, 24 May 2018 06:42:05 GMT

thanks.