Continuous-time delta-sigma modulator
AssigneeKorea University Research and Business Foundation
InventorsChulwoo KIM, Chaekang LIM
Life of this patent
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Abstract
A continuous-time delta-sigma modulator includes a loop filter, a quantizer, a finite impulse response (FIR) filter, and a digital to analog converter. The loop filter integrates a difference between an input signal and a feedback signal. The quantizer quantizes a signal output from the loop filter to convert the quantized signal into a digital signal. The FIR filter performs an FIR filtering process on the digital signal output from the quantizer. The digital to analog converter converts a signal output from the FIR filter into an analog signal and outputs the converted analog signal as a feedback signal.
Claims6
A continuous-time delta-sigma modulator, comprising:
- a loop filter which integrates a difference between an input signal and a feedback signal;
- a quantizer which quantizes a signal output from the loop filter to convert the quantized signal into a digital signal;
- a finite impulse response (FIR) filter which performs a FIR filtering process on the digital signal output from the quantizer;
- and
- a digital to analog converter which converts a signal output from the FIR filter into an analog signal and outputs the converted analog signal as a feedback signal;
- wherein the loop filter is implemented by at least one Gm-C integrator, and
- wherein the at least one Gm-C integrator includes:
- a transconductor which generates differential output currents through a plus output terminal and a minus output terminal in accordance with a difference of input voltages input to a plus input terminal and a minus input terminal;
- and
- first and second capacitors which receive the differential output current to charge charges and generate an integrated voltage.
(canceled)
A loop circuit, comprising:
- a transconductor which converts a difference of input voltages input to two differential input terminals(Vinp, Vinn) into a current and outputs the current;
- first and second capacitors which accumulate charges by a current output from the transconductor;
- and
- a chopper circuit which is located at a front-end or a rear-end of the transconductor and removes a low frequency noise.
Dependencies are inferred from the claim text.