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 Author Topic: What is arduino Uno's ADC input Current Min and Max?  (Read 1550 times) 0 Members and 1 Guest are viewing this topic.
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 « on: January 07, 2012, 12:16:51 pm » Bigger Smaller Reset

What is arduino Uno's ADC input Current Min and Max? Is the input min 40mA?
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 « Reply #1 on: January 07, 2012, 12:36:44 pm » Bigger Smaller Reset

The inputs all have a very high resistance, so it will only draw a very small current. In order to draw more current, it must be at a higher voltage. Anything above 5V and it will be damaged.

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 « Reply #2 on: January 07, 2012, 03:33:04 pm » Bigger Smaller Reset

They are high impedance input and will draw only uA.
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 « Reply #3 on: January 07, 2012, 08:43:37 pm » Bigger Smaller Reset

The ADC inputs are voltage sensing, and not current sensing. They are high impedance and will put little load on a circuit. The do not sink, they just sense. They do not draw any current, they sense voltage.

They have a MAX of 5V DC. If you need to sense a higher voltage you will need to make a voltage divider using a couple resistors in series.
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 « Reply #4 on: January 07, 2012, 09:16:18 pm » Bigger Smaller Reset

What is arduino Uno's ADC input Current Min and Max? Is the input min 40mA?

Min is about 0V and max is about whatever VCC is set to.

Analog in and probably tolerate 40mA.  However, since AnalogIn is a voltage measurement, the question of why such high current needs to be asked.
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 « Reply #5 on: January 07, 2012, 10:24:02 pm » Bigger Smaller Reset

Also the analog pins can source/sink current if set as output in software.
Code:
pinMode(A1, OUTPUT);
In such case, their current capacity is the same as the other digital pins, 40ma absolute max <30ma recommended.

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 « Reply #6 on: January 09, 2012, 02:19:13 pm » Bigger Smaller Reset

Quote
What is arduino Uno's ADC input Current Min and Max?
The minimum current is 0uA the maximum is 1uA as specified in the data sheet Section 28 under input leakage current.
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