ADS1115 overvoltage with differential measurements

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Ryry
 
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ADS1115 overvoltage with differential measurements

Post by Ryry »

If a higher voltage than the maximum allowed for the ADS1115 was introduced will it damage the Arduino Due or other breakouts that I have connected? The ADS1115 is powered at 4.8V (Arduino Due 5V output pin) and the ADS datasheet shows no more than 0.3V greater than VDD so, 5.1V is the maximum allowed to the ADS. The SDL/SDA communication lines on the ADS1115 are connected to a bi-directional logic level converter so it doesn't damage the Due since they operate on 3.3V and 5V. If I introduce 5.5 volts or 6V...10V to the ADS1115 inputs, what are the consequences of this? I am measuring differential voltage across all four inputs. Thank you.

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sj_remington
 
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Re: ADS1115 overvoltage with differential measurements

Post by sj_remington »

If I introduce 5.5 volts or 6V...10V to the ADS1115 inputs
It will immediately be destroyed. The ADS1115 does not tolerate the slightest abuse (I know this from personal experience).

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adafruit_support_bill
 
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Re: ADS1115 overvoltage with differential measurements

Post by adafruit_support_bill »

The datasheet lists the "Absolute Maximum" rating for analog input voltages as "VDD + 0.3V"
https://www.ti.com/lit/ds/symlink/ads1115.pdf
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

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sj_remington
 
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Re: ADS1115 overvoltage with differential measurements

Post by sj_remington »

Some people have been confused by the "differential" measurements, thinking that negative input voltages are allowed.

They are not! As the data sheet also mentions, analog input voltages < GND - 0.3V exceed the absolute maximum rating and will also immediately destroy the device.

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