I am trying to build a stock of essential components. For transistors/MOSFETS I think I'll go with this ones:
NPN: 2N2222
PNP: 2N2907
N-MOSFET: BUZ11
P-MOSFET: FQP27P06
Not sure about the P-MOSFET though. Which one would you recommend?
I am also looking for a Zener Diode to prevent backfeeding to the Digital I/O pins. Which one would you recommend?
Get Logic Level, Low Rds N-channel and P-channel MOSFETs, they will turn full on with 5V signals.
BUZ11 and FQP27P06 are 'standard' gate MOSFETs, needing 10V to fully turn on.
I like the AOI-514, 516, 518 parts
I like NDP6020P-ND
backfeeding? only applies if you are driving inductive loads where collapsing magnetic field can create voltage spikes on the driving pin.
Zealot:
I am also looking for a Zener Diode to prevent backfeeding to the Digital I/O pins. Which one would you recommend?
No, just make the clock/data pins INPUTs when powering down the NeoPixels,
then they take no current - you can high-side or low-side switch the NeoPixel
string since its running at 5V, so whichever terminal you disconnect the string will be within
the 0V to 5V range needed for Arduino pins.
The real backpowering risk would be if powering down the Arduino while connected to
a powered-up device.
CrossRoads:
backfeeding? only applies if you are driving inductive loads where collapsing magnetic field can create voltage spikes on the driving pin.
I want to completely switch off Neopixels (to save power). See: Strange WS2812 NeoPixel backfeed current. FYIO
MarkT:
... you can high-side or low-side switch the NeoPixel string since its running at 5V, so whichever terminal you disconnect the string will be within
the 0V to 5V range needed for Arduino pins.
N-channel seems to be a bad idea. See: http://forums.adafruit.com/viewtopic.php?f=47&t=46885&p=235562#p235570 ("... I already said I tried switching the ground and that resulted in smoke ...").
The real backpowering risk would be if powering down the Arduino while connected to
a powered-up device.
Seems like a (possible?) catch-22. I could use a P-channel, make sure I first power down the Neopixels, after that put the Arduino to sleep. But will the Arduino maintain HIGH (on the pin that drives the P-channel) after it's in sleep mode?
When using MOSFETs, it is common to put a resistor (10k-100k) between source and gate - thus, if nothing else is acting on the gate (ie, the pin is tristated because the Arduino is in reset), you're sure that the fet will stay off.
Hi, I like THIS one:
Data: Drain to Source On Resistance rDS(ON) ID = 30A, VGS = 5V, 0.047 Ω
So nice hard turn-on with arduino output pin. Get the spec sheet HERE:
I looked at many, asked opinions here on the forum first.
Complementary PFET HERE:
DISCLAIMER: Mentioned stuff from my own shop...
terryking228:
Hi, I like ...
Can you also recommend a good
cheers.
What voltage zener? 5.1V?
What current rating schottky? 1A enough?
CrossRoads:
What voltage zener? 5.1V?
What current rating schottky? 1A enough?
Yes and yes 