The OP8666 uses four (4) microcontroller internal ADC units, responsible for the conversion of 16 analog channels.
The OP8666 provides eight (8) 16-bit differential mode channels and eight (8) 12-bit single ended channels.

Each ADC channel has a pre-buffer stage, which sets high impedance to the input, while increasing the input voltage range to ±10V which is commonly used by most HIL simulators and high accuracy sensors.
Simultaneous sampling is possible only on channels belonging to different ADC units.
The 16-bit channels can convert at 1.1Msps, while the 12-bit channels can convert at 3.5Msps, when only a single channel of a particular ADC unit is used.

The following table provides essential information regarding the possible configurations of the ADC units.

ADC Units	Channel Count	Configuration	Min Acquisition Time (ns)	Min Sample Hold Time
ADC-A	3	16-Bit Differential	320	29.5 ADC Clock Cycles
ADC-B	3	16-Bit Differential	320	29.5 ADC Clock Cycles
ADC-C	2	16-Bit Differential	320	29.5 ADC Clock Cycles
ADC-D	8	12-Bit Single Ended	75	10.5 ADC Clock Cycles

Hardware Products Documentation

OP8666 Analog to Digital Conversion

Input Equivalent Circuit