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
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/
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/
6 posts
• Page 1 of 1
Please be positive and constructive with your questions and comments.
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
-
adafruit_support_bill - Posts: 83823
- Joined: Sat Feb 07, 2009 10:11 am
You can use a voltage divider to reduce an input voltage to the allowable range.
-
sj_remington - Posts: 362
- Joined: Mon Jul 27, 2020 4:51 pm
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????
-
AsifSaeed - Posts: 8
- Joined: Wed Mar 24, 2021 6:48 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.
The voltage divider solution suggested by sj_remington is a bit simpler.
-
adafruit_support_bill - Posts: 83823
- Joined: Sat Feb 07, 2009 10:11 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
-
AsifSaeed - Posts: 8
- Joined: Wed Mar 24, 2021 6:48 am
6 posts
• Page 1 of 1
Please be positive and constructive with your questions and comments.