Signal modulation circuit
AssigneeOnkyo Corporation
InventorsYoshinori NAKANISHI, Tsuyoshi KAWAGUCHI, Mamoru SEKIYA
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Abstract
Provided is a modulation circuit that can correct an output state in real time and reliably modulate an input signal to output the modulated signal. The signal modulation circuit includes a subtractor, an integrator, a chopper circuit, a frequency divider, and a D-type flip-flop. A delay circuit of a sigma delta modulation circuit is not provided to a feedback circuit, and a signal is delayed and quantized in the D-type flip-flop. The chopper circuit inserts a zero level at timing synchronized with a clock signal, so that pulse density modulation is performed.
Claims5
A signal modulation circuit for performing delta sigma modulation on an input signal in synchronization with a clock signal to output the modulated signal, the circuit comprising:
- a subtractor for calculating a difference between the input signal and a feedback signal;
- an integrator for integrating an output signal from the subtractor;
- a zero level inserting circuit for inserting a zero level into the signal integrated by the integrator at timing synchronized with the clock signal;
- a quantizer for delaying the signal output from the zero level inserting circuit and quantizing the delayed signal;
- and
- a feedback circuit for feeding back the signal quantized by the quantizer to the input signal.
-11. (canceled)
Dependencies are inferred from the claim text.