Partially implemented devices

[FabriceSalvaire]

Unimplemented value types

• NonLinearVoltageSource E
  NonLinearCurrentSource G
  raw_spice should help to pass unimplemented value types

Unimplemented node/value types

• XSpiceElement A

Low priority

• GSSElement N TCAD not documented in Ngspice manual

[HGrabas]

I have checked and implementing the PULSE ngspice source using as_A definition makes a functional pulsed current source. See code below.

This is useful to have - and maybe that coud be included in the next release.

Comes the question of the implementation. In ngspice there is no distinction between a pulsed voltage source or a pulsed current source other that the units of the initial values being V or A.

So

Vpulse source 0 PULSE(0V 12V 4e-08s 0s 0s 2e-09s 1s)
implements a pulsed voltage source
Ipulse source 0 PULSE(0A 0.006A 100ns 0s 0s 1ns 1us)
implements a pulsed current source.

There are both PULSE

In PySpice
class PySpice.Spice.HighLevelElement.Pulse(name, node_plus, node_minus, initial_value, pulsed_value, pulse_width, period, delay_time=0, rise_time=0, fall_time=0)

inherits from PySpice.Spice.BasicElement.VoltageSource

So this limits the pulse source to a voltage one even though it should be possible to have pulsed current source.

It is my understanding that a similar argument could be made for PWL sources.

class IPulse(CurrentSource):

    """This class implements a pulse waveform.

    Nomenclature:

    +--------+---------------+---------------+-------+
    | Name   + Parameter     + Default Value + Units |
    +--------+---------------+---------------+-------+
    | I1     + initial value +               + V, A  |
    +--------+---------------+---------------+-------+
    | I2     + pulsed value  +               + V, A  |
    +--------+---------------+---------------+-------+
    | Td     + delay time    + 0.0           + sec   |
    +--------+---------------+---------------+-------+
    | Tr     + rise time     + Tstep         + sec   |
    +--------+---------------+---------------+-------+
    | Tf     + fall time     + Tstep         + sec   |
    +--------+---------------+---------------+-------+
    | Pw     + pulse width   + Tstop         + sec   |
    +--------+---------------+---------------+-------+
    | Period + period        + Tstop         + sec   |
    +--------+---------------+---------------+-------+

    Spice Syntax::

        PULSE ( I1 I2 Td Tr Tf Pw Period )

    A single pulse so specified is described by the following table:

    +-------------+-------+
    | Time        | Value |
    +-------------+-------+
    | 0           | I1    |
    +-------------+-------+
    | Td          | I1    |
    +-------------+-------+
    | Td+Tr       | I2    |
    +-------------+-------+
    | Td+Tr+Pw    | I2    |
    +-------------+-------+
    | Td+Tr+Pw+Tf | I1    |
    +-------------+-------+
    | Tstop       | I1    |
    +-------------+-------+

    Note: default value in Spice for rise and fall time is the simulation transient step, pulse
    width and period is the simulation stop time.

    Public Attributes:

      :attr:`delay_time`

      :attr:`fall_time`

      :attr:`initial_value`

      :attr:`period`

      :attr:`pulse_width`

      :attr:`pulsed_value`

      :attr:`rise_time`

    """

    ##############################################

    def __init__(self, name, node_plus, node_minus,
                 initial_value, pulsed_value,
                 pulse_width, period,
                 delay_time=0, rise_time=0, fall_time=0):

        # Fixme: default
        #  rise_time, fall_time = Tstep
        #  pulse_width, period = Tstop

        super().__init__(name, node_plus, node_minus)

        self.initial_value = as_A(initial_value)
        self.pulsed_value = as_A(pulsed_value)
        self.delay_time = as_s(delay_time)
        self.rise_time = as_s(rise_time)
        self.fall_time = as_s(fall_time)
        self.pulse_width = as_s(pulse_width)
        self.period = as_s(period) # Fixme: protect by setter?

        # # Fixme: to func?
        # # Check parameters
        # found_none = False
        # for parameter in ('rise_time', 'fall_time', 'pulse_width', 'period'):
        #     parameter_value = getattr(self, parameter)
        #     if found_none:
        #         if parameter_value is not None:
        #             raise ValueError("Parameter {} is set but some previous parameters was not set".format(parameter))
        #     else:
        #         found_none = parameter_value is None

    ##############################################

    @property
    def frequency(self):
        return self.period.frequency

    ##############################################

    def format_spice_parameters(self):

        # Fixme: to func?
        return ('PULSE(' +
                join_list((self.initial_value, self.pulsed_value, self.delay_time,
                           self.rise_time, self.fall_time, self.pulse_width, self.period)) +
                ')')

####################################################################################################

[FabriceSalvaire]

Current sources are implemented in devel branch

see https://github.com/FabriceSalvaire/PySpice/blob/devel/PySpice/Spice/HighLevelElement.py