Puls Current

Symbol

Information

A Pulsed Current Source generates a square wave current signal based on the following equation:

\[\begin{split}I(t) = \begin{cases} I_a + I_{off}, & 0 \leq t < D \cdot T \\ I_{off}, & D \cdot T \leq t < T \end{cases}\end{split}\]

Where:

• \(I(t)\) is the output current at time \(t\)

• \(I_a\) is the amplitude of the pulse current (Amperes)

• \(I_{off}\) is the offset current (Amperes)

• \(T\) is the period of the waveform (Seconds)

• \(D\) is the duty cycle (Percentage, %)

Ports

• p: Positive terminal

• n: Negative terminal

Model

The PulsCurrent model generates a square wave current signal.

This model is useful for modulated current sources, digital circuits, and switching power applications.

Attributes:

• I (signal): Output current through terminals (p, n).

• Ia (param): Amplitude of the pulse current, default is 1 A.

• T (param): Period of the waveform, default is 0.1 sec.

• D (param): Duty cycle percentage, default is 50%.

• Ioff (param): Offset current, default is 0 A.

Methods:

analog(): Implements the square wave current output equation.

\[\begin{split}I = \begin{cases} I_a + I_{off}, & \text{when pulse is ON} \\ I_{off}, & \text{when pulse is OFF} \end{cases}\end{split}\]

from pyams.lib import model, signal, param, time
from pyams.lib import current

class PulsCurrent(model):
    """
    Pulsed Current Source Model.
    """

    def __init__(self, p, n):
        # Signal declaration
        self.I = signal('out', current, p, n)

        # Parameter declarations
        self.Ia = param(1.0, 'A', 'Amplitude of square wave current')
        self.T = param(0.1, 'Sec', 'Period')
        self.D = param(50, '%', 'Duty cycle')
        self.Ioff = param(0.0, 'A', 'Offset current')

    def analog(self):
        """Defines the square wave pulse current equation."""
        t = time.value  # Get the current simulation time
        cycle_time = t % self.T  # Time within the current period

        if cycle_time <= (self.D / 100.0) * self.T:
            self.I += self.Ia + self.Ioff  # Pulse ON
        else:
            self.I += self.Ioff  # Pulse OFF

Command syntax

The syntax for defining a pulsed current source in a PyAMS simulation:

# Import the model
from pyams.models import PulsCurrent

# Iname: is the name of the current source instance
# p, n: The connection points in the circuit
Iname = PulsCurrent(p, n)