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Pot and program selection pins max current ??
Posted: Sat Nov 23, 2019 3:50 am
by gkaiomenos
Hello!
I want to control the pot and program selection pins via a microcontroller / dac.
Do we know the maximum current these pins get?
Re: Pot and program selection pins max current ??
Posted: Sat Nov 23, 2019 9:54 am
by frank
We never measured those specific parameters but the POT inputs are 10M minimum input impedance and the switch inputs are normal digital inputs so they will also be high input impedance. Basically shouldn't be an issue for any micro to drive them.
Re: Pot and program selection pins max current ??
Posted: Sun Nov 24, 2019 6:47 am
by gkaiomenos
frank wrote: ↑Sat Nov 23, 2019 9:54 am
We never measured those specific parameters but the POT inputs are 10M minimum input impedance and the switch inputs are normal digital inputs so they will also be high input impedance. Basically shouldn't be an issue for any micro to drive them.
Thanks for the swift reply Frank!
At the moment I'm thinking of an unbuffered DAC with 1ma max drive current per output. Do you think it would be possible to drive these pins with no issues??
Re: Pot and program selection pins max current ??
Posted: Sun Nov 24, 2019 9:55 am
by frank
Should be no problem, these things are normally in the microamp range.
You may want to check if the DAC requires a minimum load some do to operate properly so the input impedance may be too high and you need to add a load resistor.
Re: Pot and program selection pins max current ??
Posted: Sun Nov 24, 2019 12:25 pm
by ice-nine
You may need to check that the voltage is in range as well, if using a micro like the Arduino at 5v you will need to allow for 3.3v for S0-S2 and for the pot inputs you\may need to add PWM filtering.
Re: Pot and program selection pins max current ??
Posted: Sun Nov 24, 2019 1:17 pm
by gkaiomenos
frank wrote: ↑Sun Nov 24, 2019 9:55 am
Should be no problem, these things are normally in the microamp range.
You may want to check if the DAC requires a minimum load some do to operate properly so the input impedance may be too high and you need to add a load resistor.
ice-nine wrote: ↑Sun Nov 24, 2019 12:25 pm
You may need to check that the voltage is in range as well, if using a micro like the Arduino at 5v you will need to allow for 3.3v for S0-S2 and for the pot inputs you\may need to add PWM filtering.
Thanks again Frank!
It will be with an atmega running at 3.3V so I guess voltage range should be good.