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Author Topic: A10 current sink  (Read 2193 times)

kantal

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A10 current sink
« on: April 24, 2014, 12:21:06 PM »
Hi!
 
 I'm playing with A10Lime. What resistor should be applied if a pin is used as input? I could not find anything about current sink.( I am inexperienced in electronics:( )

Thanks

dave-at-axon

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Re: A10 current sink
« Reply #1 on: April 24, 2014, 01:54:55 PM »
You don't have to worry about sinking on an input as they are generally very low current, in the uA range.

The resistor  value will depend on how fast the input is changing but a 4K7 to 10K resistor as pullup or pulldown will work fine for "slowish" inputs.

Devices like the A10 and A20 have built in resistors that you can enabled via software. You might find that the value is suitable for your application and this removes the need and cost of an external resistor. :)

kantal

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Re: A10 current sink
« Reply #2 on: April 24, 2014, 04:41:21 PM »

So, can I power the input pin with 3.3V without a resistor?

dave-at-axon

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Re: A10 current sink
« Reply #3 on: April 24, 2014, 06:48:04 PM »
Basically yes.

When you say 3.3V, I assume you mean a device with 3.3V output or do you mean to connect the 3.3V power rail to the input. Either way, it will work.

kantal

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Re: A10 current sink
« Reply #4 on: April 24, 2014, 07:13:44 PM »
Thank you!