| 摘要 |
PROBLEM TO BE SOLVED: To provide aΔ-Σmodulator that can correct the amplitude of a signal at an input unit of a quantizer while at the same time suppressing an increase thereof, can do without an internal DA converter, and can attain the reduction of power consumption in the entire circuit. SOLUTION: AΔ-Σmodulator includes at least one integrator INT11, a quantizer Quan11 that quantizes an output signal of the integrator INT11 and outputs a digital signal, and a compensation unit that compensates for nonideal characteristics caused by an internal loop delay. The compensation unit is formed with a feedback path from an output terminal of the quantizer Quan11 to an input terminal of the integrator INT11 immediately before the quantizer, wherein the feedback path has no frequency characteristics. The compensation unit includes a digital-analog (DA) converter DAC11 that converts a digital signal generated by the quantizer Quan11 to an analog signal and a capacity C<SB>DAC</SB>connected in series with an output terminal of the DA converter, and has a function to compensate for nonideal transfer characteristics between input and output caused by a loop delay. COPYRIGHT: (C)2011,JPO&INPIT
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