ADS1115 16 bit ADC

Moderators: adafruit_support_bill, adafruit

Forum rules
Talk about Adafruit Raspberry Pi® accessories! Please do not ask for Linux support, this is for Adafruit products only! For Raspberry Pi help please visit: http://www.raspberrypi.org/phpBB3/
Locked
User avatar
AsifSaeed
 
Posts: 10
Joined: Wed Mar 24, 2021 6:48 am

ADS1115 16 bit ADC

Post by AsifSaeed »

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

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: ADS1115 16 bit ADC

Post by adafruit_support_bill »

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

User avatar
sj_remington
 
Posts: 998
Joined: Mon Jul 27, 2020 4:51 pm

Re: ADS1115 16 bit ADC

Post by sj_remington »

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

User avatar
AsifSaeed
 
Posts: 10
Joined: Wed Mar 24, 2021 6:48 am

Re: ADS1115 16 bit ADC

Post by AsifSaeed »

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????

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: ADS1115 16 bit ADC

Post by adafruit_support_bill »

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.

User avatar
AsifSaeed
 
Posts: 10
Joined: Wed Mar 24, 2021 6:48 am

Re: ADS1115 16 bit ADC

Post by AsifSaeed »

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

Locked
Forum rules
Talk about Adafruit Raspberry Pi® accessories! Please do not ask for Linux support, this is for Adafruit products only! For Raspberry Pi help please visit: http://www.raspberrypi.org/phpBB3/

Return to “Adafruit Raspberry Pi® accessories”