I would like to use STM32f407 discovery board for ECU design. So I used battery=12V and I have to design Buck converter but I didn't find anywhere discovery board electrical characteristic. How much amper is fit discovery board? Please help me.

[KnarfB]

https://www.st.com/en/evaluation-tools/stm32f4discovery.html

[AEKME.1]

Thank you ,

Please read carefully. I didn't see anywhere input current specifications.

 Board power supply: through USB bus or from an external 5 V supply voltage

 External application power supply: 3 V and 5 V

Power supply and power selection

The power supply is provided either by the host PC through the USB cable, or by an external 5V power supply.

The D1 and D2 diodes protect the 5V and 3V pins from external power supplies:

• 5V and 3V can be used as output power supplies when another application board is connected to pins P1 and P2. In this case, the 5V and 3V pins deliver a 5V or 3V power supply and power consumption must be lower than 100 mA.

• 5V can also be used as input power supplies e.g. when the USB connector is not connected to the PC. In this case, the STM32F4DISCOVERY board must be powered by a power supply unit or by auxiliary equipment complying with standard EN-60950-1: 2006+A11/2009, and must be Safety Extra Low Voltage (SELV) with limited power capability.

So I didn't see anywhere current recommend or electrical charecteristic. Could I recalculate the schematic?

[KnarfB · Accepted solution]

You're right. USB 2.0 5V means max. 500 mA. I don't have that board handy, but a similar one: nucleo-F446re.

It registers itself in USB with MaxPower: 0x96 (300 mA). When I hook up a USB meter, I measure ~65mA when the board is idle or "blinky".

The overall current depends on the peripherals you are using (on-chip+off-chip).

hth

KnarfB

[TDK]

Current consumption is listed in the datasheet: https://www.st.com/resource/en/datasheet/dm00037051.pdf

Keep in mind this doesn't take into account current draw from other components on the board.

[AEKME.1]

Thank you so much :)

If usb 2.0's current enough this card I will calculate the this card need 500ma if extra situation happened.

[AEKME.1]

You're right so I'm confused about component selection. Also I would like to use buck converter. Do you suggest LDO or switching buck converter ?

Thank you for information

[Ozone]

> I would like to use STM32f407 discovery board for ECU design.

You are quite tight-lipped about your ECU application.

But many ECUs require either extended temperature range (to 125°C), or safety features for the controller, or both.

Check before you start developing.

[AEKME.1]

You're right also any component don't have AEC qualified. But this design is demo for my thessis. If it is not stabil applcation I will design new control card instead of discovery board. Also I didn't get any component abroad for Covid 19. Thank you for warning .

[Ozone]

For a thesis, temperature range is most probably of much concern.

But many applications require fail-safe operations, which imply specials efforts per software, or special controllers.

Doing controllers for heavy machinery, my company now changed to a dual-core Cortex R4 with safety coprocessor.

I would check the objectives of your thesis, perhaps you don't need that either.

For hardware, I'm not the right guy.