Recommend a 24-bit ADC module (not a chip), preferably with the same pin definition as the attachment, 12 pins, SPI interface...

QWE4562009

Recommend a 24-bit ADC module (not a chip), preferably with the same pin definition as the attachment, 12 pins, SPI interface... [Copy link]

 

Recommend a 24-bit ADC module (not a chip), preferably with the same pin definition as the attachment, 12pin, SPI interface, dual channel, 3.3V power supply

aallian

I know an I2C interface, HX711

huo_hu

It is not enough to make capacitor filtering for 24-bit ADC power supply. High-precision voltage regulation is required, and the analog input pins must also be designed for filtering.

Another thing is that it is meaningless if you have the pin order but no package model

QWE4562009

aallian posted on 2020-3-17 18:22 I know an I2C interface, HX711

The electronic scale is not accurate enough.

QWE4562009

huo_hu posted on 2020-3-18 23:57 It is not enough to make capacitor filtering for 24-bit ADC power supply. High-precision voltage regulation is required, and the analog input pins must also be designed for filtering; another thing is that you have pins...

10uA/0.01uA=1000 times. So a 10-bit ADC is enough. Why do some people use 24 bits, which is 16777216, to sample this signal? Isn't that a waste? The actual AD value is only tens of thousands, full range.

huo_hu

QWE4562009 posted on 2020-3-19 18:12 10uA/0.01uA=1000 times. If you calculate it this way, a 10-bit ADC is enough. Why do some people use 24...

Yes, don't use 24 bits if you don't need it. High precision has a price. What is 10uA? Please describe your design in full.

huo_hu

I have used that chip on the electronic scale, and it can't reach 24 bits at all. It's just 24 bits of data, and the last few bits are not used at all.

QWE4562009

huo_hu posted on 2020-3-20 22:30 I have used the chip of the electronic scale, and it can't reach 24 bits at all. It only has 24 bits of data, and the following bits are not used at all

Shouldn't the value of 24-bit AD be in the range of 16777216? Why is the maximum AD in the group software only 32799? Isn't this a waste of resources? 10uA is the maximum range and 0.01uA is the resolution

wsmysyn

QWE4562009 posted on 2020-3-23 11:13 Shouldn't the value of 24-bit AD be in the range of 16777216? Why is the largest AD in the group software I see now only 32799? What's the reason...

This requires distinguishing between the number of data bits and the number of ADC bits, which are not the same concept.

The number of data bits is defined, such as which ones are sampling values and which ones have other meanings, such as channel encoding, or other meanings, or even have no meaning at all.

You need to read the manual and operating instructions.

huo_hu

QWE4562009 posted on 2020-3-23 11:13 Shouldn't the value of 24-bit AD be in the range of 16777216? Why is the largest AD in the group software I see now only 32799? What's the reason...

It seems that your design does not have an op amp for conditioning, which will not work. The current to be measured must be adjusted to a suitable voltage range before measuring.

QWE4562009

huo_hu posted on 2020-3-23 22:57 It seems that your design does not have an op amp for conditioning, which will not work. The current to be measured must be adjusted to a suitable voltage range before measuring.

What is the appropriate voltage range? Power rail?

huo_hu

QWE4562009 Published on 2020-3-24 11:59 What is the appropriate voltage range? Power rail?

It is the reference voltage REF+ REF-

Please describe your design in full, maybe we have a ready-made chip or solution.

QWE4562009

huo_hu posted on 2020-3-18 23:57 It is not enough to make capacitor filtering for 24-bit ADC power supply. High-precision voltage regulation is required, and the analog input pins must also be designed for filtering; another thing is that you have pins...

How many digits are actually significant in 24 bits?

huo_hu

QWE4562009 posted on 2021-3-1 15:49 How many effective digits are there in 24 digits?

This is hard to say, and it has a lot to do with the peripheral circuit

QWE4562009

huo_hu posted on 2021-3-3 16:13 This is hard to say, it has a lot to do with the peripheral circuit

For example, what about the peripheral circuit?

QWE4562009

huo_hu posted on 2020-3-24 16:01 QWE4562009 posted on 2020-3-24 11:59 What is the appropriate voltage range? Power rail? It is the reference voltage REF+ REF- ...

It's the chip for body fat scales. Any recommendations?

huo_hu

QWE4562009 posted on 2021-3-5 16:43 For example, what about the peripheral circuit

Reference voltage, signal conditioning, wiring, component placement, filter circuit..

huo_hu

QWE4562009 posted on 2021-3-5 16:50 This is the chip for body fat scales. Do you have any recommendations?

I bought ads modules before, there were more than 20 or 100 of them, I don't remember the model