Randomizer for sigma delta type converter
AssigneeSTMicroelectronics S.r.I.
InventorsVittorio Colonna, Andrea Baschirotto, Gabriele Gandolfi
Life of this patent
Estimating the term…
Abstract
A sigma-delta-type converter comprises: a sigma-delta modulator having a digital output having a first prefixed bit number; a randomizer including a circular memory; an analogical reconstruction filter comprising a branch number equal to said first default number including sampling capacitors and a low-pass filter; characterized in that said circular memory comprises a number of elements equal to said first default number of bits less one and receives in input said first default number of bits less one, and in that a bit of said first default number of bits is applied to one of said branches of said reconstruction filter.
Claims22
Sigma delta type converter comprising:
- a sigma delta modulator having a digital output having a first prefixed bit number;
- a randomizer including a circular memory;
- an analogical reconstruction filter comprising a branch number equal to said first default number including sampling capacitors and a low pass filter;
- characterized in that said circular memory comprises a number of elements equal to said first default number of bits less one and receives in input said first default number of bits less one, and in that a bit of said first default number of bits is applied to one of said branches of said reconstruction filter.
Method for carrying out a sigma delta type conversion comprising the phases of providing at the output of a multi bit sigma delta modulator a default number of bits;
- applying at a randomizer a number of bits equal to said default number of bits less one;
- applying the outputs of said randomizer to corresponding inputs of an analogical-digital converter;
- applying a bit provided by said sigma delta modulator to an input of said analogical-digital converter with capacitors.
A sigma-delta analog-to-digital converter, comprising:
- a modulator operable to receive an input analog signal and to generate a first number of data bits in response to the signal;
- a circular memory coupled to the modulator and operable to store a second number of the data bits generated by the modulator, the second number less than the first number;
- and
- a reconstruction filter operable to receive the second number of bits from the circular memory, to receive the remaining of the first number of bits from the modulator, and to generate an output analog signal in response to the received bits.
A circuit, comprising:
- a circular memory operable to receive and store a first number of data bits;
- and
- a reconstruction filter operable to receive the first number of data bits from the circular memory, to receive a second number of data bits, and to generate an analog signal in response to the first and second numbers of data bits.
A method, comprising:
- randomly ordering a first set of bits;
- and
- converting a digital value into an analog signal, the digital value including the randomly ordered first set of bits and a second set of bits.
Dependencies are inferred from the claim text.