I'm Looking for a MCU with at least 20 I/Os with independent supply with CAN!

[Joerg1]

I can't choose this with the product selector (at least I don't know how :-))

Could you please help?

Thanks a lot.

Joerg

[Ozone]

Not sure what exactly you mean.

Modern MCUs, including STM32's, are mostly IOs. You can map several peripheral functions to each pin, including standard GPIO and CAN.

Unlike old designs like PIC16/PIC18, which has a lot of dedicated pins.

Just select a MCU with CAN in the product selector, and read over the datasheet.

> Could you please help?

You could get more precise help if you give more info, like performance requirements (core performance, peripheral throughput) for your application.

[Danish1]

Please explain what you mean by "independent supply".

Do you (for example) mean I/Os that are

• not electrically related to any of the microcontroller's power rails? There are none like that, but you can use opto-isolation to achieve this.
• Using a different Vdd from the main microcontroller Vdd? Some have a few I/O that are on VddIO2 e.g. PORTG on stm32L4, but never as many as 20. But you can use level-shifter ICs to do this.
• Able to deliver high current? You'll need buffer ICs / relays / whatever depending on what you want to drive.
• Or something else. If so, what?

[Joerg1]

Al right, sorry for my bad explanation and thank you for the quick reply. 

I'm new with STM32 Microcontroller, but I worked with PIC18 few years ago, so there is some experience :-).

I found on the STM32F072x8 datasheet, that they have "Up to 68 I/Os with 5V tolerant capability and 19 with independent supply VDDIO2".

My idear is to connect VDDIO2 with a separate low noise reference source because I want to switch through an FSR array for pressure measurement.

But the array has 20 rows. That`s why I'm looking for one with 20 I/Os with VDDIO2.

I thought that the VDDIO2 is a special feature which I can search for with a kind of selection table.

Since the application is very slow, there are just very few performance requirements.

If I know the MCUs with 20 I/Os connected to VDDIO2, together with CAN feature, I can choose the best fitting one. 

It seems that I have to look on each MCU datasheet with CAN, to find one with 20 I/Os supporting VDDIO2 - right? 

Thank you very much,

Joerg

[waclawek.jan]

What' you've found is probably the most. AFAIK, VDDIO2 is in the F0 of which 'F07x and 'F09x are the biggest; then in 'L07x but there it supplies only 2 pins; and then - as Danish said above - in 'L47x, supplying PORTG's pins, i.e. up to 16.

JW

[Joerg1]

Thank you, it seams that there are no more than 19 available :(

It's a pitty, one too less.

Joerg