The use of unipolar loop signals in the error diffusion modulator

The error diffusion architecture allows analog to digital conversion provided a bipolar representation is used in the signal processing. In cases when unipolar signal processing is used, the usual architecture must be modified. Changing the usual quantization threshold of the one bit quantizer within the architecture is sufficient when the ratio of the output levels of the quantizer is two or less. When the ratio exceeds two then the range of the input signal must be specially restricted. This work has applications in unipolar signal processing such as NMOS and optical signal processing.