Power Button mechanism and Auto Power On


We designed a number of carrier boards for TX1 and TX2 modules before. Now, we are working on a carrier board design for Xavier modules. We will have a carrier board without any power button mechanism so the board will be powered on by an adapter and we want the board to power on without need of a power button. We did this mechanism easily on TX1/2 modules easily before but same mechanism for Xavier boards seem a bit complicated when we look at schematics and OEM design guide.

So, to achieve this mechanism for Xavier modules without an MCU, how can we implement power button circuitry? I guess we must use SRC0CS25D chip. We dont need power-off sequence in the board. The guide says we need to connect ACOK signal to ground but we dont have this signal in our design. In carrier board schematics this signal is just connected to MCU pins but there is no connection in SRC0CS25D chip.

So, how we will achieve this functionality with SRC0CS25D chip?

Also, what is the purpose of SN 74LVC1G74 chip in OEM guide? We cannot find the matching circuitry on developer kit schematics.

Hi, just need to follow the figure 11, Simplified Button Power-on Circuitry, in OEM DG and short AC_OK to ground . It is a complete design circuit for power-on no-MCU and will enable auto power on function. SN 74LVC1G74 is for signals timing setting.

Why are answers to a simple power button connection so cryptic! Just answer question with image and pin numbers! SOOOOO frustrated by a simple need to connect power button. I have a red wire and a black wire. Does the black go to pin 6 and the red to ???

The original topic here is for custom design WITHOUT power button, it is clear in OEM DG that can be reference to customer. If you have question of custom design WITH power button, you can file a new topic. Regarding your question, what the “red wire” “black wire” mean? What is the connector that the pin 6 you mentioned is of?

Hi guys,
The same answer by Trumany will be relevant for the xavier NX?