Using break function internally

Lukasz Przenioslo · ‎2015-10-21

Posted on October 21, 2015 at 14:31

Hello there,

I am working on a motor driving application (STM32F4). As for now, my circuit for sensing current and shutting down H bridge looks like this:

https://dl.dropboxusercontent.com/u/14154631/Scan%204%20Page%201.jpg

I was wondering, either it is possible to get rid of the parts in red square and use some internal peripherals of stm32f4 instead?

For this application, can for example an internal comparator be used to automatically trigger break function without any interrupts needed to be handled?

waclawek.jan · ‎2015-10-21

Posted on October 21, 2015 at 15:20

There is no analog comparator in 'F4.

JW

Lukasz Przenioslo · ‎2015-10-21

Posted on October 22, 2015 at 07:57

You are right, my mistake... Thank you. Are there any FPU based stm32 microcontrollers as powerfull as stm32f4 with comparators?

Amel NASRI · ‎2015-10-22

Posted on October 22, 2015 at 09:06

Hi Bremen,

Is it possible for you to use an STM32F3 device?

It can be the more appropriate for motor control applications.

I suggest you also have a look to

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/application_note/DM00080497.pdf

(Using STM32F3 Series PWM shut-down features for motor control and digital power conversion). It provides more details & use cases regarding the break feature.

If you will be interested on the internal interconnections of STM32F3 peripherals (TIM, COMP and others...), have a look to

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/application_note/DM00157785.pdf

(STM32F3 series peripheral interconnect matrix).

-Mayla-

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Lukasz Przenioslo · ‎2015-10-22

Posted on October 23, 2015 at 08:41

Thank you for answer,

STM32F3 are only 72Mhz. Thats over twice slower than F4 :(

AvaTar · ‎2015-10-23

Posted on October 23, 2015 at 11:34

STM32F3 are only 72Mhz. Thats over twice slower than F4 :(

And so what ?

The interesting question is, does it have the performance you need ?

And since both the F3 and F4 share the same slow Flash technology, doubled core clock does not mean double performance. And in regard to analogue periphery, the F3 is significantly better than the F4 (at least the F40x).

If you want the ultimate ARM Cortex, try an A57.

Lukasz Przenioslo · ‎2015-11-03

Posted on November 03, 2015 at 17:54

I need to perform a lot of computing operations on a regular RAM variables, thats why I am aiming for speed.