Fig. 2: RAH adapted as 8-bit DAC and 8-bit ADC.

a Diagram of an 8-bit DAC and ADC simplified circuit structure. Frequency responses of OPA, including gain bandwidth (b) and phase bandwidth (c). d Grayscale image of the digit 5 with 256 levels, with 6 selected pixel points as the input signals for the 8-bit DAC. e Entire data conversion process, including digital signal input V_in1–V_in8 (1), DAC output signal V_{out, DAC} (2), reference threshold voltage V_th for ADC (3), and ADC output signal V_{out, ADC} (4). f |V_{out, DAC}| of the 8-bit DAC corresponding to the signal input in (d) and the noise level of the circuit. The inset compares the unit quantization voltage (UQV) with noise. g V_{out, ADC} of the 8-bit ADC corresponding to the signal input in (f) and the scanning V_th. h Error analysis by comparing |V_{out, DAC}| and V_th when ADC finishes conversion.