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ADS1115 16 bit ADC
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ADS1115 16 bit ADC

by AsifSaeed on Tue Jan 25, 2022 10:55 am

Hello Guys,

I am supplying the voltage 3.3 to the ADC from raspberry pi.
Gain = 1 mean (4.09V)

My question is

is it possible for me to measure the signal greater than 3.3V upto 4.09V on any channel????

I have read, its not possible to measure the signal greater than the supplied voltage to the ADC, which is in my case 3.3V

AsifSaeed
 
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Re: ADS1115 16 bit ADC

by adafruit_support_bill on Tue Jan 25, 2022 11:07 am

is it possible for me to measure the signal greater than 3.3V upto 4.09V on any channel????

No. It is not possible to measure signals greater than VDD. And any voltage higher the VDD + 0.3V is likely to cause permanent damage to the device.
(See section 7. Absolute Maximum Ratings)
https://www.ti.com/lit/ds/symlink/ads11 ... e.com%252F

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Re: ADS1115 16 bit ADC

by sj_remington on Tue Jan 25, 2022 11:26 am

You can use a voltage divider to reduce an input voltage to the allowable range.

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Re: ADS1115 16 bit ADC

by AsifSaeed on Wed Jan 26, 2022 6:03 am

adafruit_support_bill wrote:
No. It is not possible to measure signals greater than VDD. And any voltage higher the VDD + 0.3V is likely to cause permanent damage to the device.


If i apply 5V to the ADC, then i can measure the signal on any channel upto 5V. right????

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Re: ADS1115 16 bit ADC

by adafruit_support_bill on Wed Jan 26, 2022 6:25 am

Yes. However now the i2c signals will be pulled up to 5v also, so you will need an i2c level-shifter to protect the signal pins on your Pi. https://www.adafruit.com/product/757

The voltage divider solution suggested by sj_remington is a bit simpler.

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Re: ADS1115 16 bit ADC

by AsifSaeed on Wed Jan 26, 2022 8:46 am

adafruit_support_bill wrote:Yes. However now the i2c signals will be pulled up to 5v also, so you will need an i2c level-shifter to protect the signal pins on your Pi. https://www.adafruit.com/product/757

The voltage divider solution suggested by sj_remington is a bit simpler.



great . Thank you for suport

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Joined: Wed Mar 24, 2021 6:48 am

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