I am getting confused because the components specified in it works for digital electronics
Which components do you mean?
And why should a component that works for digital circuits not be used in analog circuits? Consider a simple switch: It can be on or off, which clearly are digital states. It can switch an analog signal, e.g. mains voltage to a lamp, which is clearly an analog operation.
The datasheet specifies in the 1st paragraph:
The ADA2200 is an analog input, sampled analog output device. The signal processing is performed entirely in the analog domain by charge sharing among capacitors, which eliminates the effects of quantization noise and rounding errors. The ADA2200 includes an analog domain, low-pass decimation filter, a programmable infinite impulse response (IIR) filter, and a mixer. This combination of features reduces ADC sample rates and lowers the downstream digital signal processing requirements.
All procerssing is done in the analog domain (amplification, filtering, sampling). The ADC mentioned here is a separate component downstream (after the output of the ADS2200).
The (digital) SPI Interface is for programming the operating parameters of the device only.
A clock section is required for the synchronous demodulation (turning the demodulator switches on and off).
The signal path is analog, however.
