STM32F746 DISCO and standby mode

[Ehill.16]

I have removed the display on the DISCO board and I am just using a small OLED for a display. I have a couple of other things connected to the board. A TMP1075 EVM and a TMP390 EVM. I am measuring about 410 mA in run mode. When I invoke standby mode, the current drops to about 175 mA. Does this sound right. Reading the datasheet, the STM32F746 should have a current draw in the uA range.

[waclawek.jan]

410mA doesn't sound like consumption of the 'F7 alone, either.

The Disco boards, especially the high-end ones, are perhaps not the best candidates for a low-consumption experiments. Too many onboard chips. Make sure all of them are "shut down" in some way. Make sure all their IOs (and all IOs of the mcu itself) are in a non-floating low-consuming state.

JW

[Ehill.16]

The 410 mA is for the DISCO board. It is a STM32F746 DISCO board.

[Ehill.16]

I have read about the GPIO pins needing to be in a non floating state. So I have to set up every pin in this state!

[waclawek.jan · Accepted solution]

> The 410 mA is for the DISCO board. It is a STM32F746 DISCO board.

Yes, and 175mA is the same board, isn't it, so it's not just the consumption of STM32F7xx itself.

If you want to measure STM32's consumption separately, from the schematics it appears that you could measure STM32's supply current by removing R21 and replacing it by any current measuring arrangement of yours. Be careful not to power up the board without powering the mcu.

JW

[Ehill.16]

Thanks JW!

[Piranha]

Read AN4899, especially section 6. AN4749 also has some useful information.