Decoding, encoding/decoding and converting
View Patent ↗Implementations and embodiments of decoders, encoder/decoder systems and converters are depicted and described.
1. A decoder comprising:
an input to receive a time-encoded signal;
a filter which is coupled to the input;
a sampler which has a signal input which is coupled to an output of the filter;
an edge detector, comprising an input coupled to the input of the decoder, and comprising an output coupled to a clock signal input of the sampler; and
an asynchronous to synchronous converter, comprising a signal input coupled to the output of the sampler, and an output coupled to an output of the decoder.
2. The decoder according to claim 1 , further comprising an interpolator coupled to the sampler.
3. A converter comprising:
an input;
an output; and
a encoding/decoding system, the encoding/decoding system comprising:
an encoder to generate a time encoded input signal;
a decoder comprising an input coupled to an output of the encoder, the decoder comprising:
an edge detector, comprising an input coupled to the input of the decoder;
a first sampler, comprising a signal input coupled to the input of the decoder and a clock signal input coupled to an output of the edge detector; and
an asynchronous to synchronous converter, comprising an input coupled to the output of the first sampler, and an output coupled to an output of the encoding/decoding system.
4. The converter according to claim 3 , wherein an out-put of the encoding/decoding system is also coupled via a backward path to the input of the encoding/decoding system.
5. The converter according to claim 3 , wherein the encoder comprises a first and second loop filter.
6. The converter according to claim 3 , wherein the converter comprises a first and second feedback loop.
7. The converter according to claim 3 , wherein the encoder comprises a second sampler.
8. The converter according to claim 3 , wherein the first and second sampler are implemented to operate at a first oversampling rate.
9. The converter according to claim 3 , wherein the asynchronous to synchronous converter is further implemented to decimate the oversampling rate of the output signal of the converter from the first oversampling rate to a second oversampling rate.
10. The converter according to claim 3 , wherein the encoder comprises a loop filter, and the decoder comprising a filter simulating a filter function of the loop filter.
11. A converter comprising:
an input to receive an analog signal;
an output to provide a digital signal;
a first encoding circuit coupled to the input, the first circuit comprising a self-oscillating pulse width modulator to provide an oversampled single-bit signal with an oversampling frequency;
a second decoding circuit coupled to the first circuit to receive the oversampled single-bit signal and configured to provide a digital signal with a sampling frequency lower than the oversampling frequency to the output;
a feedback path coupled to the first circuit to feed back to the noise shaping filter an analog signal based on the over-sampled single-bit signal.
12. The converter according to claim 11 , wherein the noise shaping filter is a higher-order noise shaping filter.
13. The converter according to claim 11 , wherein the noise shaping filter is coupled via a digital-to-analog converter to the first circuit.
14. The converter according to claim 11 , wherein the second circuit comprises a filter having a filter function with a zero at the limit cycle frequency of the self-oscillating pulse width modulator.
15. The converter according to claim 11 , wherein the noise shaping filter is implemented to shape a quasi-periodic signal concentrated at a predetermined frequency.
16. The converter according to claim 11 , wherein the feedback path is a feedback path of the self-oscillating pulse width modulator and the noise shaping filter and a loop filter of the self-oscillating pulse width modulator are implemented in a same loop filter.
17. The converter according to claim 11 , wherein the feed back path comprises a single bit digital-to-analog converter coupled to the first circuit to receive the oversampled single-bit signal and coupled to the noise shaping filter to provide an analog signal based on the oversampled single-bit signal.
18. A converter comprising:
an input to receive an analog signal;
an output to provide a digital signal;
a first circuit coupled to the input, the first circuit comprising a self-oscillating pulse width modulator to provide an oversampled single-bit signal with an oversampling frequency, the self-oscillating pulse width modulator comprising a first feedback path and a loop filter;
a second decoding circuit coupled to the first circuit to receive the oversampled single-bit signal and configured to provide a decoded digital signal with a sampling frequency lower than the oversampling frequency to the output; and
a noise shaping filter; and
a second feedback path to feed back an analog signal based on the oversampled single-bit signal to the noise shaping filter.
19. The converter according to claim 18 , wherein the noise shaping filter is implemented in a feed forward path of the first circuit between the input and the self-oscillating pulse width modulator.
20. The converter according to claim 18 , wherein the second decoding circuit comprises a digital filter with a filter function, the filter function having a zero corresponding to the limit cycle frequency of the self-oscillating pulse width modulator.
21. The converter according to claim 18 , wherein the second decoding circuit comprises a digital decimator filter with a filter function corresponding to a filter function of the loop filter.
22. The converter according to claim 18 , wherein the noise shaping filter is implemented in a feed forward path of the first circuit.
23. The converter according to claim 18 , further comprising a single-bit digital-to-analog converter coupled between an output of the first encoding circuit and the loop filter.
24. The converter according to claim 18 , wherein an input of the noise shaping filter is coupled to an output of the loop filter.