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Thread: Can teensy 3.5 withstand a short 8V power spike?

  1. #1
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    Can teensy 3.5 withstand a short 8V power spike?

    Hello, My 5V DC-DC converter spikes to ~8V for a fraction of a second when I first plug in the circuit. I see that teensy ( I have 3.2 and 3.5) can only take up to 6V in Vin but I was wondering if a short power spike like that is acceptable.

  2. #2
    Senior Member PaulStoffregen's Avatar
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    Yes, the LP38691 voltage regulator on those boards is actually rated up to 10 volts, so a brief 8V spike is probably fine.

    The 6V rating on Teensy 3.x is based on using a sustained 250 mA current from the 3.3V pin. While the LP38691 can go up to 10V input and up to 500 mA current, its total power dissipation is limited by heating too much.

  3. #3
    Although if your input is 12V or more, I would also wonder about whether the 8V you measured is the actual maximum value, or if sometimes (depending on temperature, input voltage etc.) it may go higher still. I think a well-designed converter really should ramp up from 0 to the setpoint on startup, and not generate an excessive voltage under any conditions.

    I like the sub-$1 DC-DC converters on ebay for 12V, 24V -> 5V based on the MP1584EN chip. Now you have me wondering if they have an overshoot on startup- I've never actually looked at that.
    Last edited by JBeale; 09-08-2017 at 12:19 AM.

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    i have a few of these from fleabay that i use with my projects
    inputs are 8-40V DC and output is 5V 30A, 3.3V 30A, and 12V 6A, theres prolly other voltage outputs as well, but i got these and found them very useful, and also, ifbyou plan to use it in your vehicle, it survives cranks and voltage doesnt fluctuate. the high amperage output is good for led setups as well, theyre epoxy sealed, and seems to run cool (no heat on aluminum casing)

  5. #5
    Senior Member pictographer's Avatar
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    Those wires look way too thin for 5V 30A. Typo?

  6. #6
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    not a typo, my entire car project is running off one 5V 30A of those, including 2 5V lcds and a servo and a chaos amount of additional circuits lol, T3.5 is the HOST


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  7. #7
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    Wow! Thanks!

  8. #8
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    i just went to finger test the temperature of it, its not even warm, still cold, runs 24/7

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