ADPD105 register 0x18~0x21 was the ADC offset register,default is 0x2000.
In general,how to setting this value?
When operating the device in normal mode, with zero input current, the device output will be at ~mid-scale. You can use the ADC offset registers to effectively "null" this offset. It's simply a digital subtraction of the ADC output minus the setting of the ADC offset register on a per pulse basis.