Can RT1170/RT1160 NVCC_xxx IO Supply Voltage be 2.5V?

[mrd]

Can anyone could confirm that 2.5V on one of the IO supply's such as NVCC_DISP1 would be okay? I think the answer is "yes" as long as we can operate with the NVCC "Derated voltage range" thresholds and timing in the Industrial datasheet's table 37 and 40. The reason we want to use 2.5V is for interfacing to a Gigabit Ethernet Phy that requires 2.5V levels.

I'm asking because the industrial datasheet table 8 "Absolute Maximum Ratings" and table 11 "Operating ranges" only has specifications for "3.3 V mode" and "1.8 V mode", which is worded similar to the reference manual's section 21.3.1 "Application Mode" where it talks about the "Application Mode" set by DCDC_MODE and DCDC_IN has to either be fed by 3.3V or 1.8V. I just wanted to make sure NVCC GPIO IO supply doesn't really need to be within a range around 3.3V or 1.8V, but that it can be in-between at 2.5V.

Thank you!

[kerryzhou]

Hi @mrd ,

   About the power on, it has the defined range, plesae refer to the RT1170 hardware guide:

https://www.nxp.com/webapp/Download?colCode=MIMXRT1170HDUG

So, you can't use other voltage, if you need 2.5V, you may need to use the level switch chip to meet your external chip demand.

Wish it helps you!

If you still have questions about it, please kindly let me know.

Best Regards,

kerry

[mrd]

Thank you for the reply, but I'm not understanding.

The link you provided is for MIMXRT1170HDUG (Hardware Development Guide for the MIMXRT1160/1170 Processor). I don't see anything in it about NVCC_xxx voltage requirements.  Sorry if I've overlooked it.  Please point out what I'm missing.

The table excerpt in your post is from the IMXRT1170IE datasheet table 11 which I also referenced in my original post. It shows Operating Ranges for the "3.3V mode" and "1.8V mode". Are you saying that DCDC_MODE (which sets Application Mode) determines whether we are operating in "3.3V mode" or "1.8V mode" and NVCC (such as NVCC_DISP1) must be in these ranges? If so, what is the datasheet's table 37 and 40 indicating when it has "Derated voltage range" conditions? Look at datasheet Table 37 NO. 8 where it has NVCC "Derated voltage range" of 1.98 min and 2.7 max. [The easiest is just to search the datasheet for "Derated voltage range".] Excerpt is below. Table 37 NO. 8 really seems to indicate that if a NVCC IO Supply voltage is in the "Derated voltage range" of 1.98-2.7V, then characteristics in table 37 & 40 that have Test Conditions labeled "Derated voltage range" would apply. Please explain more if this is not the case. Thank you.

Excerpt from RT1170 industrial datasheet Table 37. DC specification for GPIO_AD/GPIO_LPSR/GPIO_DISP_B2 bank.

[kerryzhou · Accepted solution]

Hi @mrd ,

   Thanks for your updated information and the patient.

   I already help you check with our internal side.

   The IO bank can be supply voltage to 2.5V when it is in the continuous mode.

   But, seems not all the GPIO bank can set the mode. 

   Eg, DISP2, this bank can select the HIGH_RANGE and LOW_RANGE to 00 in GP69, then it is the continuous range mode. Then you can power on your NVCC_DISP2 to 2.5V, and use your mentioned derated voltage range.

To the DISP1, I still didn't find the related register to control the mode, so, do you mind to use the DISP2 interface? If yes, you can power it as 2.5V.

Wish it helps you!

Any updated information, please kindly let me know.

Best Regards,

Kerry

[mrd]

Thank you for the further research on this.  I was not aware of the DISP2 high and low range settings - so this was valuable information.  We will either switch to using DISP2 or go back and find a gbit eth phy that works at either the 1.8 or 3.3V I/O levels.

[kerryzhou]

Hi @mrd ,

   Please keep patient, I will help you to check with our internal side, then give you a reply!

Best Regards,

Kerry