On the testing ADS8638 by 0V~5V input and 12bit resolution.
Expected value is 0V: 0x000 and 5V: 0xFFF, but result was 0V: 0x800 and 5V: 0xBE2. (I think that these value was received on ±10V range condition)
Please let me know need to modify point.
Test condition is below;
・DVDD and AVDD:5V, HVDD: -5V, Vref: 2.5V(REF5025A)
・Analog input: 0V~5V
・Control signal from FPGA, attached below
・SCLK: 12.5MHz
・ADC setting (by datasheet table 11~12)
①Power supply: ON
②AL_PD: Low to High
③Dummy write ×2cycle (12.5MHz: T=80ns, 80ns×20CLK×2=3.2us)
DIN set to 0x08
④Aux-Config(06h): Write to 0x08・・・DIN: set to 0x08
⑤Auto-Md Ch-Sel(0Ch): write to 0xFC・・・DIN: set to 0xFC(use CH0~5)
⑥Auto register(05h): write to 0x8C・・・DIN: set to 0x8C
Conversion range set 0V~5V, and normal AD conversion
⑦Write to 0x00 ×6, ADC read 6CH
Best regards,
Satoshi