topic Re: Power supply of s32K144 in S32K

Power supply of s32K144

ankan_creatara — Tue, 16 Aug 2022 08:50:40 GMT

Hello Everyone,

I was trying to explore the S32K144EVB. However, I came across a document, with the power supply layout of the board. I am attaching the screenshot of the same for your referral.

I wanted to check if both the marked parts (VDDA) should be same or whether the left VDDA should be only from VDD. Because, I could not relate the reason of both the marked parts being the same. It doesn't make sense.

Kindly have a look into this and help me out.

Thank you for your time.

Re: Power supply of s32K144

VaneB — Tue, 16 Aug 2022 12:04:57 GMT

Hi @ankan_creatara

VDDA and VDD are internally connected in this package. But it has a differential of 0.1V.
If externally available, connect the VDDA pin to the same voltage potential as VDD.

B.R.

VaneB

Re: Power supply of s32K144

ankan_creatara — Wed, 17 Aug 2022 07:05:54 GMT

Hello @VaneB ,

Thank you for your insights.

As far as I can understand, there is no harm in connecting both the VDD and VDDA to the same source, right!!

Re: Power supply of s32K144

VaneB — Wed, 17 Aug 2022 11:23:08 GMT

Correct, connect the VDDA pin to the same source as VDD pin.

Re: Power supply of s32K144

ankan_creatara — Mon, 22 Aug 2022 13:04:34 GMT

Hello Everyone,
I am back with some more queries. Please help me out.

In the overall schematic, and as far as I can understand; the S32K144EVB can be powered up in two ways:
1. 12V supply (external)
2. 5V from Micro-USB

Please correct me if I am wrong!!

Whenever an external 12V supply is used, the power flows through the SBC UJA1169, right? When I was exploring the UJA1169, I found out two pins in the chip:
1. Pin 5: V1
2. Pin 14: BAT

As I can see, V1 can be of 5V or 3.3V. Whereas BAT is the battery Voltage, which is of 5V. But, I could not find any port to connect the 12V from the external supply. Am I understanding the circuit correct? OR am I missing out something?

Please help me in figuring out,
A. How can I use an external 12V supply to power up the S32K144EVB. Is it even possible to use the 12V supply or Do I need to use any 5V source?
B. What is the voltage at which the entire board works? Is it 12V or 5V or 3.3V?

Thank you for your time.

Re: Power supply of s32K144

VaneB — Wed, 24 Aug 2022 09:29:47 GMT

Hi @ankan_creatara

The S32K144EVB evaluation board powers from a USB or external 12 V power supply. By default USB power is enabled with J107 jumper (2-3 closed). To enable the 12 V power you need to connect 1-2 of the J107 jumper.
You can refer the Datasheet and the application note AN5426:

S32K-DS

AN5426

B.R.

VaneB

Re: Power supply of s32K144

ankan_creatara — Thu, 25 Aug 2022 10:03:04 GMT

Hi @VaneB

Thank you for your response. I will definitely look into the attached documents.