Hi.
I already used internal ADC at XC164CS, but it has 10 bit resolution ADC. On my project, I have to get a current -250A to 150A with shunt monitor at Battery Management System(BMS). In case of 10bit ADC, there are a lot of error. Therefore, I should to use external ADC with SPI communication. But I don't know how to start. I may select 14bit ADC of TI or Analog Device, e.g, TLCL3548, ADC7856. Any one help me how to use, where to ge example source or etc..
So you want to be able to measure current in a 500A range with better than 0.1% resolution? (1 part in 2^10)
Does your current shunt have better than 0.1% accuracy? Is all your analogue circuitry better than 0.1% accuracy?
The above need to include all sources of error, noise, distortion, drift, etc, etc,...
Are you really certain that you can actually measure the difference between -250.00A and -249.52A ?
Let alone the difference between -250.00A and -249.97A ?!
Hi, make a different between resolution and presision. For example you can have a 16 Bit resolution but only 0.5% presision.
Use a 4-Wire Shunt, my recommandantation is 100uOhm.
Thanks Andy!
Actually I mean it does not need to measure precisonally in high current range, but it is important to measure exactally in low current range such as -5A to +5A.
I woud like to thanks for your opinion of ADC, But I really want to know is SPI programming with XC164CS. Especially, how to transfer command and receive data between controller and external ADC with SPI.
I used 0.1mohm(100uohm) shunt 1% tolerance.
"how to transfer command and receive data between controller and external ADC with SPI"
That will be in the Datasheet for the ADC;
And the Manufacturer's Website is the place to look for Application Notes, sample code, and other specific support information...
Thansk Andy!
I already followed your suggstion a few days ago! I think it takes time to have my own skill because I'm a beginner for SPI.