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Delta Sigma Modulator

Model a discrete delta sigma modulator based ADC

  • Library:
  • Mixed-Signal Blockset / ADC / Building Blocks

  • Delta-Sigma Modulator

Description

Use the Delta Sigma Modulator block to model a discrete delta sigma modulator based ADC using a set of different architectures. The block supports these architectures:

  • Cascade of feedback resonators.

  • Cascade of feedback integrators.

  • Cascade of feed-forward resonators.

  • Cascade of feed-forward integrators.

You can model an ADC of orders from two to six. You can also model circuit based noise.

Ports

Input

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Analog input signal, specified as a scalar.

Data Types: double

Reset signal for Delta Sigma Modulator block, specified as a scalar.

Data Types: double

Output

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Digital output signal, returned as a scalar.

Data Types: fixed point | single | double | int8 | int16 | int32 | uint8 | uint16 | uint32 | Boolean

Parameters

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Architecture of the delta sigma modulator, specified as:

  • CIFB — cascade of feedback integrators.

  • CRFB — cascade of feedback resonators.

  • CIFF — cascade of feed-forward integrators.

  • CRFF — cascade of feed-forward resonators.

Programmatic Use

Block parameter: dsmArchitecture
Type: character vector
Values: CIFB | CRFB | CIFF | CRFF
Default: CIFB

Order of delta sigma modulator. You can choose between orders two to six.

Programmatic Use

Block parameter: dsmOrder
Type: character vector
Values: 2nd order | 3rd order | 4th order | 5th order | 6th order
Default: 2nd order
Input Parameters

Sampling frequency of the delta sigma modulator, specified as a positive real scalar in Hz.

Programmatic Use

Block parameter: SamplingFrequency
Type: character vector
Values: positive real scalar
Default: 128e3

Number of quantizer levels in delta sigma modulator, specified as a positive real scalar.

Programmatic Use

Block parameter: NumberLevels
Type: character vector
Values: positive real scalar
Default: 2

Range of the quantizer output in the delta sigma modulator architecture, specified as a vector with real elements.

Programmatic Use

Block parameter: QuantizerOutput
Type: character vector
Values: real valued vector
Default: [-1;1]

Feedback coefficients from the quantizer or feed-forward coefficients to the quantizer, specified as a vector with real elements.

Programmatic Use

Block parameter: a
Type: character vector
Values: real valued vector
Default: [0.1601 0.6515]

Resonator coefficients, specified as a vector with real elements.

Programmatic Use

Block parameter: g
Type: character vector
Values: real valued vector
Default: [0.0]

Feed-in coefficients from the modulator input to each integrator, specified as a vector with real elements.

Programmatic Use

Block parameter: b
Type: character vector
Values: real valued vector
Default: [0.1601 0.6515 1]

Integrator inter-stage coefficients, specified as a vector with real elements.

Programmatic Use

Block parameter: c
Type: character vector
Values: real valued vector
Default: [1 1]
Noise

Enable noise calculations in the delta sigma modulator ADC.

Ratio of signal power to noise power, specified as a nonnegative real scalar in dB.

Programmatic Use

Block parameter: SNR
Type: character vector
Values: nonnegative real scalar
Default: 75

Power of the signal at the input of the delta sigma modulator, specified as a real scalar in watts.

Programmatic Use

Block parameter: InputPower
Type: character vector
Values: real scalar
Default: 0.125

Bandwidth of the delta sigma modulator system,

Programmatic Use

Block parameter: BandWidth
Type: character vector
Values: nonnegative real scalar
Default: 1000

Version History

Introduced in R2021b