Slew Rate

Model amplitude, rise and fall times, and propagation delay of logic gates

• Library:

• Mixed-Signal Blockset / Utilities

• 

Description

The Slew Rate block converts a logical signal to a signal with user-defined finite slew rate and propagation delay.

Ports

Input

events — Input signal

scalar

Variable step, event driven input signal, specified as a scalar. The signal at events port comes from the output of a logic gate such as Variable Pulse Delay block.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | Boolean

Output

wave — Output signal

scalar

Fixed step, uniformly sampled output signal, returned as a scalar. You can define the finite slew rate and propagation delay for the signal at the wave port.

Data Types: double

Parameters

Output step size calculation — Defines how to calculate output step size

Default (default) | Advanced

Defines how to calculate output step size.

• Choose Default to calculate Output step size calculation based on rise/fall time. The Output sample interval (ΔT) is given by $$\Delta \text{T}=\frac{{\left(\text{Rise/fall time}\right)}^2}{6·\text{ 0}\text{.22}}$$.

• Choose Advanced to calculate Output step size calculation based on frequency of interest. The Output sample interval (ΔT) is given by $$\Delta \text{T}=\frac{\text{Rise/fall time}}{6·\text{ Maximum frequency of interest}}$$.

Programmatic Use

• Use get_param(gcb,'DefaultOrAdvanced') to determine how the output step size is being calculated.

Maximum frequency of interest (Hz) — Maximum frequency of interest at output

11e9 (default) | scalar

Maximum frequency of interest at output, specified as a scalar in Hz. Maximum frequency of interest is used to calculate Output sample interval and Minimum 20%-80% rise/fall time.

Dependencies

This parameter is only available when Advanced is selected for Output step size calculation.

Programmatic Use

• Use get_param(gcb,'MaxFreqInterest') to view the current value of Maximum frequency of interest.

• Use set_param(gcb,'MaxFreqInterest',value) to set Maximum frequency of interest to a specific value.

Output sample interval — Output sample interval

23ps (default) | scalar

Output sample interval, specified as a scalar in s. This parameter is nontunable.

The Output sample interval (ΔT) is given by $$\Delta \text{T}=\frac{\text{Rise/fall time}}{6·\text{ Maximum frequency of interest}}$$.

Dependencies

This parameter is only available when Advanced is selected for Output step size calculation.

Programmatic Use

• Use get_param(gcb,'OutputSampleTime') to view the current value of Output sample interval.

• Use set_param(gcb,'OutputSampleTime',value) to set Output sample interval to a specific value.

Minimum 20%-80% rise/fall time — Minimum rise/fall time required at the output for meaningful simulation

23ps (default) | scalar

Minimum rise/fall time required at the output for meaningful simulation, specified as a scalar in ps. This is a nontunable parameter.

Dependencies

This parameter is only available when Advanced is selected for Output step size calculation.

Programmatic Use

• Use get_param(gcb,'ConversionRiseFall') to view the current value of Minimum 20%-80% rise/fall time.

• Use set_param(gcb,'ConversionRiseFall',value) to set Minimum 20%-80% rise/fall time to a specific value.

Rise/fall time (s) — 20%-80% rise time at the output

30e-12 (default) | scalar

Time required for signal to change from 20% to 80% in a full amplitude edge at the output, specified as a scalar.

Programmatic Use

• Use get_param(gcb,'RiseTime') to view the current value of Rise/fall time.

• Use set_param(gcb,'RiseTime',value) to set Rise/fall time to a specific value.

Slew rate for 20%-80% edge of unit amplitude signal — Slew rate for the 20%-80% edge at the output

56GHz (default) | scalar

Slew rate for the 20%-80% edge at the output, specified as a scalar. This parameter is nontunable.

Programmatic Use

• Use get_param(gcb,'RisingSlewRate') to view the current value of Slew rate for 20%-80% edge of unit amplitude signal.

• Use set_param(gcb,'RisingSlewRate',value) to set Slew rate for 20%-80% edge of unit amplitude signal to a specific value.

Minimum propagation delay — Minimum propagation delay for meaningful simulation

48ps (default) | scalar

Minimum propagation delay for meaningful simulation, specified as a scalar. This parameter is nontunable.

Minimum propagation delay is calculated from Maximum frequency of interest where $$\text{Minimum propagation delay =}\frac{0.269}{\text{Maximum frequency of interest}}$$.

Programmatic Use

• Use get_param(gcb,'ConversionDelay') to view the current value of Minimum propagation delay.

• Use set_param(gcb,'ConversionDelay',value) to set Minimum propagation delay to a specific value.

Propagation delay (s) — Propagation delay of a rising edge

48e-12 (default) | scalar

Propagation delay of a rising edge, specified as a scalar in s. Propagation delay is measured at a threshold equal to the half of the amplitude.

Programmatic Use

• Use get_param(gcb,'RisepropDelay') to view the current value of Propagation delay.

• Use set_param(gcb,'RisePropDelay',value) to set Propagation delay to a specific value.

Enable increased buffer size — Enable increased buffer size

button

Select to enable increased buffer size during the simulation. This increases the buffer size of all the blocks in the PLL model that belong to the Mixed-Signal Blockset™/Utilities Simulink^® library. By default, this option is deselected.

Buffer size — Buffer size of the blocks

10 (default) | positive integer scaler

Buffer size of all the blocks in the PLL model that belong to the Mixed-Signal Blockset/Utilities Simulink library.

Selecting different simulation solver or sampling strategies can change the number of input samples needed to produce an accurate output sample. Set the Buffer size to a large enough value so that the input buffer contains all the input samples required.

Dependencies

This parameter is only available when the Enable increased buffer size option is selected.

Programmatic Use

• Use get_param(gcb,'NBuffer') to view the current value of Buffer size.

• Use set_param(gcb,'NBuffer',value) to set Buffer size to a specific value.

Version History

Introduced in R2019a