I have a design where I need to power about 60 I2C hall effect sensors. Their datasheet says a typical draw of 2mA, but a max draw of 5mA. I called their tech support and they couldn't give a clear answer on when that 5mA happens, though I suspect it is when it is either actively reading or when the I2C transmission is happening.
The best case scenario is that the draw is 5mA * 1 active sensor + 2mA * 59 waiting sensors = 123 mA at any given time.
The worst case scenario is that the draw is 5mA * 60 = 300 mA at any given time.
Hence, you see the problem. The Teensy 3.2's 3.3V output is listed in the pinout document as 250mA max. I looked at the regulator IC and it can do 500mA. I looked at the main CPU and it is max 185mA. I looked at the bootloader CPU and it is max 120mA.
Now, I could add another 3.3V regulator on my carrier board, but was wondering whether I can get by with just the Teensy's regulated 3.3V output.
Any thought from those with more experience than me? Am I safe trusting that those sensors won't ever hit their max current simultaneously?
The best case scenario is that the draw is 5mA * 1 active sensor + 2mA * 59 waiting sensors = 123 mA at any given time.
The worst case scenario is that the draw is 5mA * 60 = 300 mA at any given time.
Hence, you see the problem. The Teensy 3.2's 3.3V output is listed in the pinout document as 250mA max. I looked at the regulator IC and it can do 500mA. I looked at the main CPU and it is max 185mA. I looked at the bootloader CPU and it is max 120mA.
Now, I could add another 3.3V regulator on my carrier board, but was wondering whether I can get by with just the Teensy's regulated 3.3V output.
Any thought from those with more experience than me? Am I safe trusting that those sensors won't ever hit their max current simultaneously?