Independent current source (SPICE I)#

The Independent current source (SPICE I) block is a model of a current source that is functionally similar to the independent current source of the standard SPICE libraries.

The terminal block creates current in accordance with the specified parameters.

The following output current waveforms are realized:

constant value (DC) (1) :

(1)#\[I_{out}=DC\]

sine value (SIN):

Time interval	The value of \(I_{out}\)
t < TD	V0
t \(\geq\) TD	V0 + VA \(\cdot\) sin [2\(\cdot \pi \cdot(FO \cdot (t - TD)+\frac{PH}{360})] \cdot e^{-(t-TD)\cdot DF}\)

where t is the current value of the simulation time.

exponential value (EXP):

Time interval	The value of \(I_{out}\)
t < TD1	V1
TD2 > t \(\geq\) TD1	V1 + (V2 - V1)\(\cdot\)(1- \(\frac{e^{-(t-TD1)}}{TC1}\))
t \(\geq\) TD2	V1 + (V2 - V1)\(\cdot\)[(1- \(\frac{e^{-(t-TD1)}}{TC1})\)-(1- \(\frac{e^{-(t-TD2)}}{TC2})\)]

pulse value (PULSE):

Time interval	The value of \(I_{out}\)
t < TD	V1
(TD+TR) > t \(\geq\) TD	V1 + \(\frac{(V2-V1)}{TR} \cdot\) (t - TD)
(TD+TR+PW) > t \(\geq\) (TD+TR)	V2
(TD+TR+PW+TF) > t \(\geq\) (TD+TR+PW)	V2 + \(\frac{(V1-V2)}{TF} \cdot\) (t - TD -TR - PW)
PER > t \(\geq\) (TD+TR+PW+TF)	V1

sinusoidal frequency modulated (SFFM) (2) :

(2)#\[I_{out}=F0 + VA \cdot sin [2 \cdot \pi \cdot F0 \cdot t + MI \cdot sin(2 \cdot \pi \cdot FM \cdot t)]\]

piecewise linear (PWL). The shape of the current waveform is specified by an array of time values (TIMES) and corresponding current values (VALUES).

1. Properties#

Property	Default Value	Description	Units of measurement
Type: DC; SIN; EXP; PULSE; SFFM; PWL	DC	–	–
DC - constant value	1.0	Available, when `Type` - `DC`	А
VA - peak amplitude	1.0	Available, when `Type` - `SIN` or `SFFM`	А
VO - offset value	2.0	Available, when `Type` - `SIN` or `SFFM`	А
FO - carrier frequency	8.0	Available, when `Type` - `SIN` or `SFFM`	Hz
TD - delay	0.1	Available, when `Type` - `SIN` or `PULSE`	s
DF - damping factor	5.0	Available, when `Type` - `SIN`	–
PH - phase	0.0	Available, when `Type` - `SIN`	degrees
V1 - initial value	0.6	Available, when `Type` - `EXP` or `PULSE`	А
V2 - pulse value	1.6	Available, when `Type` - `EXP` or `PULSE`	А
TD1 - rise delay	0.15	Available, when `Type` - `EXP`	s
TC1 - rise time constant	0.05	Available, when `Type` - `EXP`	–
TD2 - fall delay	0.55	Available, when `Type` - `EXP`	s
TC2 - fall time constant	0.1	Available, when `Type` - `EXP`	–
TR - rise time	0.1	Available, when `Type` - `PULSE`	s
TF - fall time	0.2	Available, when `Type` - `PULSE`	s
PW - pulse width	0.1	Available, when `Type` - `PULSE`	s
PER - period	0.5	Available, when `Type` - `PULSE`	s
MI - modulation index	4.0	Available, when `Type` - `SFFM`	–
FM - Modulation frequency	1.0	Available, when `Type` - `SFFM`	Hz
TIMES - array of time values	0.0;0.25;0.5;0.75;	Available, when `Type` - `PWL`	s
VALUES - array of signal values	1.0;0.0;2.0;1.0;	Available, when `Type` - `PWL`	А

2. Inputs and outputs#

Parameters	Input/Output	Description	Units of measurement	Port type
-	Input	Negative conclusion	-	Electronics
+	Output	Positive conclusion	-	Electronics

In order to see the connection capabilities of the block, you need to go to page Description of block ports