SaturatingAmplifier

Models a saturation amplifier

• 

Libraries:
SerDes Toolbox / Datapath Blocks

Description

The SaturatingAmplifier block scales the input waveform according to a voltage in vs. voltage out response. The voltage in vs. voltage out response is specified either by the soft clipping response defined by Limit and Linear Gain, or by the VinVout matrix. The SaturatingAmplifier block applies memoryless nonlinearity to incoming waveform.

Ports

Input

WaveIn — Input baseband signal

scalar | vector

Input baseband signal, can be a sample-by-sample signal specified as a scalar, or an impulse response vector signal.

Data Types: double

Output

WaveOut — Clipped output voltage

scalar | vector

Clipped output voltage, as specified by the SaturatingAmplifier block. If the input signal is a sample-by-sample signal specified as a scalar, the output is also scalar. If the input signal is an impulse response vector signal, the output is also a vector.

Data Types: double

Parameters

Mode — Amplifier operating mode

On (default) | Off

Amplifier operating mode:

• Off — SaturatingAmplifier is bypassed and the input waveform remains unchanged.

• On — SaturatingAmplifier scales the input waveform according to a voltage in vs. voltage out response.

Programmatic Use

• Use get_param(gcb,'Mode') to view the current saturating amplifier operating Mode.

• Use set_param(gcb,'Mode',value) to set amplifier to a specific Mode.

Specification — Input specification for limiting amplifier output

'Limit and Linear Gain' (default) | 'VinVout'

Input specification for limiting amplifier output:

• 'Limit and Linear Gain' — Creates a soft clipping voltage in vs. voltage out response with the values specified in Limit and Linear Gain.

• 'VinVout' — Generates output voltages corresponding to input voltage specified in VinVout. The block maps the input voltage to the output voltages using a memoryless nonlinearity response. If any input voltage point falls outside the specified values, the output for that particular input voltage is interpolated.

Programmatic Use

• Use get_param(gcb,'Specification') to view the current Specification of saturating amplifier.

• Use set_param(gcb,'Specification',value) to set saturating amplifier to a specific Specification.

Data Types: char

Limit — Clipping voltage for the limiting amplifier

1.2 (default) | real positive scalar

Clipping voltage for the limiting amplifier, specified as a real positive scalar in V.

Dependencies

This parameter is only available when Specification is selected as 'Limit and Linear Gain'.

Programmatic Use

• Use get_param(gcb,'Limit') to view the current value of Limit of saturating amplifier.

• Use set_param(gcb,'Limit',value) to set Limit to a specific value.

Data Types: double

LinearGain — Amplifier gain in the linear region

1 (default) | real positive scalar

Amplifier gain in the linear region, specified as a unitless real positive scalar.

Dependencies

This parameter is only available when Specification is selected as 'Limit and Linear Gain'.

Programmatic Use

• Use get_param(gcb,'LinearGain') to view the current value of LinearGain of saturating amplifier.

• Use set_param(gcb,'LinearGain',value) to set LinearGain to a specific value.

Data Types: double

VinVout — Input and corresponding output voltage responses

N×2 matrix | N×2×M matrix

Input and corresponding output voltage responses, specified as an N×2 matrix (2-D) or N×2×M matrix (3-D) in volts. N is the number of voltage samples and M is the number of slices.

If VinVout is a 3-D matrix, you can select which slice of the VinVout is to use. To know more about defining 3-D VinVout matrix, see Define Saturating Amplifier with 3D VinVout Matrix.

Dependencies

This parameter is only available when Specification is selected as 'VinVout'.

Programmatic Use

• Use get_param(gcb,'VinVout') to view the current VinVout table value of saturating amplifier.

• Use set_param(gcb,'VinVout',value) to set VinVout to a specific value.

Data Types: double

Slice select — Select which corner of 3D GPZ matrix to use

0 (default) | nonegative scalar integer

Select which slice, family, or corner of a 3-D VinVout matrix to use during CTLE configuration.

You must set the Specification parameter to 'VinVout' to effectively use the Slice Select parameter. Depending on how many slices are available in your VinVout matrix, you can then select the slice you are interested in from a zero-based index available from the dropdown menu.

Programmatic Use

• Use get_param(gcb,'SliceSelect') to view the current value of Slice select.

• Use set_param(gcb,'SliceSelect',value) to set Slice select to a specific value.

Data Types: double

Visualize Response — Plot input vs output voltage response

button

Click to plot the input vs. output voltage response of the Saturating Amplifier block.

IBIS-AMI parameters

Mode — Include Mode parameter in IBIS-AMI model

on (default) | off

Select to include Mode as a parameter in the IBIS-AMI file. If you deselect Mode, it is removed from the AMI files, effectively hard-coding Mode to its current value.

Slice select — Include Slice select parameter in IBIS-AMI model

on (default) | off

Select to include Slice select as a parameter in the IBIS-AMI file. If you deselect Slice select, it is removed from the AMI files, effectively hard-coding Slice select to its current value.

More About

Memoryless Nonlinearity

A memoryless nonlinearity (MNL) is a function where the output at the time t is only dependent on the input at the same time t. This means that the function has no memory of prior inputs and is thus memoryless. In the Saturating Amplifier block, the input voltages are mapped to the output voltage using the MNL response through a lookup table with linear interpolation between data points. This response must be a function where each input value is uniquely mapped to an output value.

Version History

Introduced in R2019a

R2023b: Slice Select

you can now select which slice, family, or corner of a 3-D GPZ matrix to use during CTLE configuration.