I endorse Dave's suggestion (below) .
The resistive divider is simple but slows down the edge rate which may
be undesirable especially if the input isnt a schmitt.
The MOSFET solution is the most appropriate. take a look what is inside
packaged translators... just that.
On 29/01/2022 10:33
Those diodes are so robust that a PIC connected the wrong way to a 5V 1 Amp
PSU was protected by all these diodes conducting in parallel and current
limiting the PSU. The PIC appeared to have survived (although I chucked
it anyway, just in case)
Andy
www.g4jnt.com
On Sat, 29 Jan 2022 at 18:56
You can run the PicDiv on 3.3 V and connect the 5V signal to the PicDiv input
via a series resistor between 1k and 10k. Put the resistor at the PicDiv end of
the connection.
The PIC has protection diodes on it's input These clamp the input to the
supply. The series resisor limits the current.
You can actually use a single small N channel MOSFET (2N7000 or similar)
with it's Gate connected to the lower Vcc via, say, a 1k resistor. (Not
strictly needed, but with long leads, it helps prevent HF transient
oscillation.
Then use it's Source as the lower voltage data line, and it's Drain
On 28/01/2022 19:41, folkert wrote:
Hi,
[]
The RPI doesn't like 5v on its GPIO pins.
So I wonder:
- can I feed the picdiv 5v on its GPIO pin while giving it a 3.3v
voltage so that it outputs 3.3v as well to the rpi pins?
- or should I use a voltage divider? I was thinking of a 4.7k ohm and
On Fri, January 28, 2022 1:41 pm, folkert wrote:
> Now I bought a "Square Wave Amplifier" by BG7TBL (
> https://www.aliexpress.com/item/4000192799858.html?gatewayAdapt=glo2nld&spm=a2g0o.9042311.0.0.3d764c4dMZPAX8
> ). Documentation I could find was a bit vague about the
> output voltage but I meas
folk...@vanheusden.com said:
> the scope software says 2MHz but output is really 10MHz).
That's one of the joys of digital scopes. You are seeing the interaction of
the sampling rate and the signal frequency.
The chart on the right says the sampling rate is 12 MS/s Try it with a
sampling ra
and unless you have LOTS of experience, avoid automatic direction
(bidirectional) translators - they are very sensitivie to pullups,
downs etc. I think best avoided unless there is no option. I2C is where
they are useful.
But otherwise, stick to unidirectional level translating as Andrew sugg
Hi
There also are logic families that are 5V tolerant when run off of 3.3V. That
makes finding a “translator” the same as finding any chip from that family.
This may or may not make things easer to do / easier to find.
One of many families is the NC7SZ series. One common gate:
https://www.onse
I find that the best way to handle these translations is to use one of
TI's level translators ... each chip has two power supply rails, and
translation is done transparently across the chip, and there is good max
voltage overprotection on both sides as well. I use them a lot to handle
5V <-> 3.3V
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