Claims
- 1. A method for adapting sigma delta modulation, the method comprising:
producing a difference signal representing the difference between an analog input signal and an adaptive feedback signal, the amplitude of the analog input signal being in a first range [−a, +a]; producing an intermediate digital signal output sequence representative of the difference signal, the amplitude of the intermediate digital output sequence being in a second range [−b, +b], wherein b<a; producing an adaptive feedback signal such that the amplitude of the adaptive feedback signal keeps the difference signal within the second range; and producing a final digital output sequence, the final digital output sequence being a function of the intermediate digital output sequence and the adaptive feedback signal.
- 2. A method according to claim 1, wherein the adaptive feedback signal is produced by estimating the instantaneous input signal and combining the estimated input signal with the sign of a quantizer output signal multiplied by an amplitude smaller than the amplitude of the input signal.
- 3. A method according to claim 1, wherein 4b=a.
- 4. A method according to claim 1, wherein-the adaptive feedback signal is delayed by one clock period.
- 5. A method according to claim 1, wherein the intermediate digital signal is produced by a sigma delta modulator is of the first order.
- 6. A method according to claim 1, wherein the sigma delta modulator is multi-ordered.
- 7. A method according to claim 1, wherein :the analog input signal is discontinuous.
- 8. A method according to claim 1, wherein the difference signal is produced by a first capacitor and the adaptive feedback signal is produced by a plurality of capacitors connected in parallel, each of the plurality of capacitors having a fraction of the capacitance of the first capacitor.
- 9. A method according to claim 8, wherein the capacitors are charged and discharged by a switch control logic device.
Parent Case Info
[0001] The present application claims priority from U.S. provisional application No. 60/118,607, filed Feb. 4, 1999, which is hereby incorporated herein by reference.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60118607 |
Feb 1999 |
US |
Continuations (2)
|
Number |
Date |
Country |
Parent |
10357613 |
Feb 2003 |
US |
Child |
10827584 |
Apr 2004 |
US |
Parent |
09496756 |
Feb 2000 |
US |
Child |
10357613 |
Feb 2003 |
US |