| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a multi-bit delta-sigma modulator and an AD converter having a wide dynamic range without a significant increase of an over sampling ratio or a circuit area. <P>SOLUTION: A multi-bit sigma-delta modulator includes an analog integrator 1 for integrating an input signal, a multi-bit quantizer for quantizing an output signal provided by the analog integrator 1 with a plurality of different quantizing steps using a plurality of threshold values Vth1, Vth2 ...Vth7, and a DA converter to feedback an output signal of the multi-bit quantizer to an input side of the analog integrator 1. The intervals between the plurality of threshold values Vth1, Vth2, ...Vth7 are configured to be gradually narrowed from a signal range intending the full scale level (+FS, -FS) of the output signal of the analog integrator 1 to a signal range intending the zero level of the output signal. <P>COPYRIGHT: (C)2012,JPO&INPIT |
