Patent ID: 9118341
Filing Date: 2015-08-25
Classification: H03M

Abstract:
1. A delta-sigma A/D converter for converting a first analog input signal into a first digital signal, and converting a second analog input signal into a second digital signal, the delta-sigma A/D converter comprising: a first quantizer that quantizes a received signal and outputs a quantized signal; a first D/A converter that converts the quantized signal outputted by the first quantizer into an analog signal, and outputs the analog signal; a first operation unit that outputs a signal indicative of a difference of the first analog input signal and the analog signal outputted by the first D/A converter; a first integrator that integrates the signal outputted by the first operation unit and outputs an integrated signal; a first dither circuit that generates a first dither signal; a second operation unit that adds the first dither signal to the integrated signal outputted by the first integrator and outputs an added signal to the first quantizer; a second quantizer that quantizes a received signal and outputs a quantized signal; a second D/A converter that converts the quantized signal outputted by the second quantizer into an analog signal, and outputs the analog signal; a third operation unit that outputs a signal indicative of a difference of the second analog input signal and the analog signal outputted by the second D/A converter; a second integrator that integrates the signal outputted by the third operation unit and outputs an integrated signal; a second dither circuit that generates a second dither signal different from the first dither signal; a fourth operation unit that adds the second dither signal to the integrated signal outputted by the second integrator and outputs an added signal to the second quantizer; and a filter that restricts a frequency band of the quantized signal outputted by the first quantizer and the quantized signal outputted by the second quantizer, and outputs the first digital signal and the second digital signal.