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I am designing a custom PCB based on an STM32 microcontroller. What is the maximum current needed as a power supply for the STM32F401RCT6? I have 3.3 V and 250 mA regulated current to power the STM32F401RCT6 microcontroller.

From the datasheet:

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enter image description here

As per the datasheet, do I need only 160 mA in total to power the microcontroller? Or do I need 100 mA for each Vdd pin? My package has 4 Vdd pins, so do I need 400 mA in total?

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Table 12 is in the section 6.2 Absolute Maximum Ratings of the datasheet. These maximum ratings are values that, if you exceed them, damage the chip.

Your normal supply currents should be much lower than these values. If that's not the case, your using the chip in the wrong way.

Table 21 are the values you need, the \$I_{DD}\$ should be the total current which, according to the table, should not exceed 24.1 mA. 4) the actual current consumption depends on how you're using the chip.

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  • \$\begingroup\$ So i should give only 24.1 mA as supply current to all VDDs or can i give 100 mA as power supply since it is less than Absolute Maximum ratings 160 mA. Because i have my regulator output as 250 mA so i should use resistors to reduce the current to 24.1 mA ? \$\endgroup\$ – Muthu Apr 19 '20 at 20:37
  • \$\begingroup\$ can i give 100 mA to the VDD so that when all the peripherals are enabled it will take 24.1 A from 100 mA am i right or Shoul i give only 24.1 mA to Vdd \$\endgroup\$ – Muthu Apr 19 '20 at 20:48
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    \$\begingroup\$ Shoul i give only 24.1 mA to Vdd No that is not how supplying power works. If you do that you would destroy the IC. You should learn how supplying power works, the supply only delivers a voltage and that voltage should match what the circuit needs. The circuit will take current. In your case I 24 mA or less. The supply needs to be able to deliver that current. A supply that can deliver 100 mA is fine. Read this as it applies: electronics.stackexchange.com/questions/34745/… \$\endgroup\$ – Bimpelrekkie Apr 20 '20 at 7:12
  • \$\begingroup\$ Thank you so much sir it was very helpfull and i understood it perfectly \$\endgroup\$ – Muthu Apr 20 '20 at 9:00
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The current drawing will depend on how the chip is used. The tables states that if all peripherals are enable you will the chip will draw up to 24.1 mA. This, however, does not include any current your I/O pins may be forced to supply to external loads. The 160 mA is the absolute maximum current chip can safely pull form the supply. This would only occur if you are heavily loading the I/O pins.

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  • \$\begingroup\$ so Can i supply 100 mA from my power supply so that when all the peripherals are enable it can draw 24.1 mA from 100 mA \$\endgroup\$ – Muthu Apr 19 '20 at 20:46
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    \$\begingroup\$ @Muthu: the power supply must provide AT LEAST 24.1 mA. The chip will only draw the current it requires - there is no problem if the supply can provide more, even much more, than the chip requires. \$\endgroup\$ – Peter Bennett Apr 19 '20 at 22:23
  • \$\begingroup\$ Thank you so much \$\endgroup\$ – Muthu Apr 20 '20 at 8:55
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Your regulator can provide up to 250mA. But the load will take only as much as current it needs. The MCU itself will never take more than what is listed, about 25 mA. But if you drive loads that need current, like LEDs, they add up. You are not allowed to exceed 160mA total on the power pins. In practice, you are not allowed to exceed 120mA total for non-power pins so you won't get near 160mA ever.

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