Hi,
We have built 1st prototype of our new design, based on ads131m08, 8 chan 24bit ADC.
We are using the internal 1.2V vref, with OSR=16384, Clk in = 2MHz
Topic 1
After performing some tests, I would like to get more info regarding calibration process, data sheet section 8.3.11
There are the following registers for each channel: OCALn[23:0] and GCALn[23:0]
Do you have an app note, with exact procedures, step by step, on how to perform calibration process?
Topic 2
Using data sheet section 8.3.2 Input Multiplexer, we are setting ALL channels to MUX0[1:0] to MUX7[1:0] = 10 --> inserting the positive test signal to all channel.
We are using internal reference voltage of 1.2V, all calibration registers are at default values.
Measured results:
Chan0[V] |
Chan1[V] |
Chan2[V] |
Chan3[V] |
Chan4[V] |
Chan5[V] |
Chan6[V] |
Chan7[V] |
0.153128 |
0.159142 |
0.153057 |
0.15319 |
0.152856 |
0.152971 |
0.152312 |
0.153071 |
Per data sheet we should get exact 160mV…
Chan1 is the closest to this value, but the remain have large error
Can you share more info on that? Are we doing something wrong?
This is also related to calibration process
Regards,
Eran