Patent US714445A successfully refreshed from Google Patents.
EP0328318A2
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EP
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Delta-sigma modulator
Assignee: Denso Ten Ltd
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Filing: 1989-02-03
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Granted: —
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Expires: 2009-02-03
Abstract
Abstract The delta-sigma modulator includes a secondary delta-sigma modulator (100) which carries out a secondary delta-sigma modulation for an analog input signal (Ain), thereby producing a first quantization signal (DILO). A quantization noise extractor (200) extracts a quantization noise occurring in the secondary delta-sigma modulator. A primary delta-sigma modulator (300) carries out a first delta-sigma modulation for the quantization noise, thereby producing a second quantization signal (DIL1). A differentiating circuit (28) differentiates the second quantization signal supplied from the primary delta sigma modulator: An adder (29) adds the first quantization signal and an output signal of the differentiating circuit, thereby producing a digital output signal (Dout) corresponding to the analog input signal.
Inventors
- 👤 Seiji Endo
- 👤 Osamu Kobayashi
- 👤 Masatsugu Kamimura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 20:25
CPC Classifications
H; H03; H03M; H03M3/00; H03M3/02; H04; H04B; H04B14/00; H04B14/02; H04B14/04; H04B14/046; H03M3/30; H03M3/39; H03M3/412; H03M3/414; H03M3/418
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
119 words
A delta-sigma modulator, characterized by comprising secondary delta-sigma modulation means (100) for carrying out a secondary delta-sigma modulation for an analog input signal (Ain), thereby producing a first quantization signal (DILO); quantization noise extracting means (200) for extracting a quantization noise (Q1) occurring in said secondary delta-sigma modulation means; primary delta-sigma modulation means (300) for carrying out a first delta-sigma modulation for said quantization noise, thereby producing a second quantization signal (DIL1); differentiating means (28) for differentiating said second quantization signal supplied from said primary delta-sigma modulation means; and adding means (29) for adding said first quantization signal and an output signal of said differentiating means, thereby producing a digital output signal (Dout) corresponding to said analog input signal.
Claim 2
Dependent Claim
119 words
A delta-sigma modulator, characterized by comprising secondary delta-sigma modulation means (100) for carrying out a secondary delta-sigma modulation for an analog input signal (Ain), thereby producing a first quantization signal (DILO); quantization noise extracting means (200) for extracting a quantization noise (Q1) occurring in said secondary delta-sigma modulation means; primary delta-sigma modulation means (300) for carrying out a first delta-sigma modulation for said quantization noise, thereby producing a second quantization signal (DIL1); differentiating means (28) for differentiating said second quantization signal supplied from said primary delta-sigma modulation means; and adding means (29) for adding said first quantization signal and an output signal of said differentiating means, thereby producing a digital output signal (Dout) corresponding to said analog input signal.
Claim 3
Dependent Claim
59 words
A delta-sigma modulator as claimed in claim 1, characterized in that the secondary delta-sigma modulation means comprises first-and second-stage integral circuits (21, 22) cascaded, and a first quantizer (24) having an input terminal connected to said second-stage integral circuit (22) and said quantization noise extracting means (200), and an output terminal connected to said quantization noise extracting means (200).
Claim 4
Dependent Claim
50 words
A delta-sigma modulator as claimed in claim 2, characterized in that said quantization noise extracting means (200) comprises a subtracter (28) having a first input terminal connected to the input terminal of said first quantizer (24), and a second input terminal connected to the output terminal of said first quantizer.
Claim 5
Dependent Claim
29 words
A delta-sigma modulator as claimed in any of claims 1 to 3, characterized in that said differentiating means comprises first and second differentiating portions (k, I) which are cascaded.
Claim 6
Dependent Claim
51 words
A delta-sigma modulator as claimed in any of claims 1 to 4, further comprising delay means (70, 52, 53, 54) for delaying said first quantization noise by a predetermined time so as to fit, on the time axis, said first quantization signal into the output signal of said differentiating means (28).
Claim 7
Dependent Claim
59 words
A delta-sigma modulator as claimed in any of claims 2 to 5, characterized in that said secondary delta-sigma modulation means (100) comprises corresponding switched capacitor means (42), and said delta-sigma modulator further comprises first switch control means (26) for generating switch control signals (P1, P2) to be supplied to said switched capacitor means by using said first quantization signal.
Claim 8
Dependent Claim
59 words
A delta-sigma modulator as claimed in any of claims 1 to 6, characterized in that said primary delta-sigma modulator means (300) comprises switched capacitor means (42, 44), and said delta-sigma modulator further comprises second switch control means (27) for generating switch control signals (P3, P4) to be supplied to said switched capacitor means by using said second quantization signal.
Claim 9
Dependent Claim
55 words
A delta-sigma modulator as claimed in any of claims 1 to 7, said the first quantization signal derived from said secondary delta-sigma modulation means (100) has the following transfer characteristic: where F is said first quantization signal, Ain is said analog input signal, Q1 denotes said quantization noise, and z- 1 denotes a unit delay.
Claim 10
Dependent Claim
46 words
A delta-sigma modulator as claimed in claim 8, characterized in that said second quantization signal derived from said primary delta-sigma modulator (300) has the following transfer characteristic: where J is the second quantization signal, Q2 is a quantization noise occurring in said primary delta-sigma modulator (300).
Claim 11
Dependent Claim
24 words
A delta-sigma modulator as claimed in claim 9, characterized in that the output signal of said differentiating means (28) has the following transfer characteristic:
Claim 12
Dependent Claim
26 words
A delta-sigma modulator as claimed in claim 10, characterized in that the digital output signal derived from said adding means (29) has the following transfer characteristic:
References Cited (Backward Citations)
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