| Trilobite 1.4 User Guide | © Darwin Arts L.L.C., 2016

# Pulse Width Modulator Module

The Pulse Width Modulator module generates a variety of different pulse types, where each pulse occurs over a configurable duration of a duty cycle (full frequency period of the pulses). Using the input port values and static parameters, the single pulse duration may be configured to be a portion of or completely independent of the duty cycle. See the Static Parameters section below for more details.

For a key to understanding the tables on this page, see the Module Types page.

| The Pulse Width Modulator module is available in Pro Version only.

## Adding Input Ports

Adding input ports is not enabled for this module.

## Static Parameters

  # | Title | Type | Description
  0 | Pulse Type | Choice | Supported pulse waveforms include: Sine Period, where the pulse waveform is a single sinusoid period. Square Period, where the pulse is a single square wave period. Triangle Period, where the pulse is a single triangle wave period. Sawtooth Period, where the pulse is a single sawtooth wave period. Hanning Pulse, where the pulse is a Hann Function with smooth rise and decay transitions. Square Pulse, where the pulse is a square window function. Parabolic Pulse, where the pulse is a parabola function with sharp rise and decay transitions. Glottal Pulse, where the pulse is the idealized “tear drop” shape with gradual rise and sharp decay which emulates the physical glottal stop characteristics of the human vocal tract. Inverse Glottal Pulse, which is simply a backwards glottal pulse function with sharp rise and smooth decay. Cardinal Sine Pulse, where the pulse is a normalized sinc function.
  1 | Modulation Type | Choice | This parameter selects how each pulse is placed and shaped within its duty cycle. Available options are: Stretched and Offset. The pulse duration is an adjustable ratio of the duty cycle period based on input to Port 1, and offset into duty cycle specified by input into Port 2. Note that this option will truncate whatever portion of the pulse lies beyond the duty cycle. Period Locked. The pulse duration is an adjustable ratio of the duty cycle period based on input to Port 1, and always begins at the start of the duty cycle. Input to Port 2 is not used. Shape Modulated. The pulse duration is an adjustable ratio of the duty cycle period based on input to Port 1, and begins at the start of the duty cycle. Input to Port 2 will determine the stretch distortion of the pulse to the left or right.

## Input Ports

  # | Title | Description | Input Scalar Used | Parameter Scalar Used
  0 | Frequency | Input to this port determines the frequency of the pulse modulator duty cycle. | YES | YES
  1 | Pulse Width | Input to this port determines the proportionate width of the pulse function relative to the duty cycle period. | NO | YES
  2 | Modulator | Use of input to this port varies based on the Modulation Type static parameter selection. See Modulation Type description above for more details. | NO | YES

## Output Ports

  # | Title | Description
  0 | Periodic Pulse | The period pulse signal.