2017-04-19 07:26 AM
Hi,
I have designed low power detector with using stm32f030f4p6. In normal state detector is supplied with 24Vdc and it consumes 50uA. But when I supply the detector with 2V, mcu consumes 2mA. This high current consumption is very important, because when energized the alarm panel after connect 30 detectors, detectors input voltage increase slowly and all detectors cause the high current consumption at 2V levels.
When I read the dataheet, detector enters the reset state at 2V. In this state, it consumes 2mA. Is it normal? Or are there any solution to fix this?
Sorry for my poor English.
Thanks in advance.
2017-04-20 12:24 AM
While in reset the mcu runs from its HSI - 2mA sounds like the expected power consumption.
JW
2017-04-21 06:36 AM
I studied a little more and noticed that mcu consumes 2 mA from its Vdd input. There is no consumption on Vdda input. Internal 1.8V voltage regulator and xtal osc are supplied from Vdd input. I don't use external osc. in the design so 1.8V regulator can cause this current consumption.
If I use the L0 series mcu, do I have the same problem?
2017-04-21 03:19 PM
Even if you would have an external crystal or oscillator, during reset - which is below 2V - the internal HSI is running and you can't do anything about it.
I am afraid the same is valid for the 'L0 and all the other STM32s.
I recommend you to reconsider the power supply circuit - post the details of it, or better, post relevant portions of schematics, if you wish to discuss it here.
JW