WOLFRAM SYSTEM MODELER

AD_Converter

Simple n-bit analog to digital converter

Wolfram Language

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SystemModel["Modelica.Electrical.Analog.Ideal.AD_Converter"]
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Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

Simple analog to digital converter with a variable resolution of n bits. It converts the input voltage ppin.v-npin.v to an n-vector of type Logic (9-valued logic according to IEEE 1164 STD_ULOGIC). The input resistance between positive and negative pin is determined by Rin. Further effects (like input capacities) have to be modeled outside the converter, since this should be a general model.

The input signal range (VRefLo,VRefHi) is divided into 2^n-1 equally spaced stages of length Vlsb:=(VRefHi-VRefLo)/(2^n-1). The output signal is the binary code of k as long as the input voltage takes values in the k-th stage, namely in the range from Vlsb*(k-0.5) to m*(k+0.5). This is called mid-tread operation. Additionally the output can only change its value if the trigger signal trig of type Logic changes to '1' (forced or weak).

The output vector is a 'little-endian'. i.e., that the first bit y[1] is the least significant one (LSB).

This is an abstract model of an ADC. Therefore, it can not cover the dynamic behaviour of the converter. Hence the output will change instantaneously when the trigger signal rises.

Parameters (4)

N

Value:

Type: Integer

Description: Resolution in bits - output signal width

VRefHigh

Value:

Type: Voltage (V)

Description: High reference voltage

VRefLow

Value:

Type: Voltage (V)

Description: Low reference voltage

Rin

Value:

Type: Resistance (Ω)

Description: Input resistance

Connectors (4)

p

Type: PositivePin

Description: Positive electrical pin (input)

n

Type: NegativePin

Description: Negative electrical pin (input)

y

Type: DigitalOutput[N]

Description: Digital output

trig

Type: DigitalInput

Description: Trigger input

Used in Examples (1)

AD_DA_conversion

Modelica.Electrical.Analog.Examples

Conversion circuit

Revisions

  • October 13, 2009 by Matthias Franke