Diode (SPICE model)#

The Diode (SPICE model) block is a SPICE model of a diode with a parallel resistance added to account for leakage effects. The block implements the following equivalent circuit :

The equivalent circuit contains the following elements:

\(C_d\) – p-n junction capacitance. Determined analytically depending on the block parameters and the voltage at the p-n junction;
\(I_d\) – current source that generates the p-n junction current. It is determined analytically depending on the block parameters and the voltage at the p-n junction;
\(R_L\) – active resistance simulating parasitic parallel resistance (leakage effect);
\(R_S\) – active resistance simulating parasitic series resistance.

A block can implement one of two conditions:

the presence of a nonlinear dependence on temperature;
absence of nonlinear dependence on temperature.

The general equation for the two temperature-dependent conditions is the equation (1):

(1)#\[VT=\frac{k \cdot T}{q}\]

where:

\(k\) is the Boltzmann constant, \(k=1.38 \cdot 10^{-23}\) [J/K];

\(T\) is the diode temperature, [K];

\(q\) is the elementary electric charge of an electron, \(q=1.602 \cdot 10^{-19}\) [C].

In the absence of a nonlinear dependence on temperature, the following equations are used (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12) :

(2)#\[I_{nrm}=IS \cdot (e^{\frac{U_d}{VT\cdot N}}-1)\]

(3)#\[\begin{split}K_{inj} =\begin{cases}\sqrt{\frac{IKF\cdot AREA}{IKF \cdot AREA +I_{nrm}}} , & \ IKF>0\\1,& \ IKF=0 \end{cases}\end{split}\]

(4)#\[I_{rec}=ISR \cdot (e^{\frac{U_d}{VT\cdot NR}}-1)\]

(5)#\[K_{gen}=((1-\frac{U_d}{VJ})^2 + 0.005)^{M/2}\]

(6)#\[I_{fwd}=I_{nrm} \cdot K_{inj}+I_{rec} \cdot K_{gen}\]

(7)#\[I_{rev}= IBV \cdot AREA \cdot (e^{-(\frac{U_d+BV}{VT \cdot NBV})}-1)+IBVL \cdot AREA \cdot (e^{-(\frac{U_d+BV}{VT \cdot NBVL})}-1)\]

(8)#\[I_d=I_{fwd}-I_{rev}\]

(9)#\[G_d=\frac{dI_{vd}}{dU_d}\]

(10)#\[CT=TT \cdot G_d\]

(11)#\[\begin{split}CJ =\begin{cases} CJO \cdot(1-\frac{U_d}{VJ})^{-M}, & \ U_d \leq FC \cdot VJ\\CJO \cdot (1-FC)^{-(1+M)}\cdot (1-FC \cdot(1+M)+M \cdot \frac{U_d}{VJ}),& \ U_d>FC \cdot VJ \end{cases}\end{split}\]

(12)#\[C_d=CT+CJ\]

In the presence of a nonlinear dependence on temperature, the following equations are used (13), (14), (15), (16), (17), (18), (19), (20), (21), (22), (23), (24), (25), (26), (27), (28), (29), (30), (31), (32) :

(13)#\[IS(T)=IS \cdot AREA \cdot e^{((\frac{T}{TMEAS}-1)\cdot\frac{EG}{VT \cdot N})}\cdot (\frac{T}{TMEAS})^{\frac{XTI}{N}}\]

(14)#\[ISR(T)=ISR \cdot AREA \cdot e^{((\frac{T}{TMEAS}-1)\cdot\frac{EG}{VT \cdot NR})}\cdot (\frac{T}{TMEAS})^{\frac{XTI}{NR}}\]

(15)#\[IKF(T)=IKF \cdot AREA \cdot (1+TIKF \cdot (T-TMEAS))\]

(16)#\[BV(T)=BV \cdot (1+TBV1 \cdot (T-TMEAS) + TBV2 \cdot (T-TMEAS)^2)\]

(17)#\[RS(T)=RS \cdot (1+TRS1 \cdot (T-TMEAS) + TRS2 \cdot (T-TMEAS)^2)\]

(18)#\[EG_{TMEAS}=1.17 - \frac{0.000702 \cdot T^2}{TMEAS+1108}\]

(19)#\[EG_T=1.16 - \frac{0.000702 \cdot T^2}{T+1108}\]

(20)#\[VJ(T)=VJ\cdot(\frac{T}{TMEAS})-3 \cdot VT \cdot ln(\frac{T}{TMEAS})-EG_{TMEAS}(\frac{T}{TMEAS})+EG_T\]

(21)#\[CJO(T)=CJO\cdot AREA(1+M \cdot(0.0004 \cdot (T-TMEAS)+(1-\frac{VJ(T)}{VJ})))\]

(22)#\[I_{nrm}=IS(T)\cdot(e^{(\frac{U_d}{VT \cdot N})}-1)\]

(23)#\[\begin{split}K_{inj} =\begin{cases} \sqrt{\frac{IKF \cdot AREA}{IKF \cdot AREA + I_{nrm}}}, & \ IKF>0\\1,& \ IKF=0\end{cases}\end{split}\]

(24)#\[I_{rec}=ISR(T)\cdot(e^{(\frac{U_d}{VT \cdot NR})}-1)\]

(25)#\[K_{gen}=((1-\frac{U_d}{VJ(T)})^2+0.005)^{M/2}\]

(26)#\[I_{fwd}=I_nrm \cdot K_{inj}+I_{rec}\cdot K_{gen}\]

(27)#\[I_{rev}=IBV \cdot AREA \cdot (e^{-(\frac{U_d+BV(T)}{VT \cdot NBV})}-1)+IBVL \cdot AREA \cdot (e^{-(\frac{U_d+BV(T)}{VT \cdot NBVL})}-1)\]

(28)#\[I_d=I_{fwd}-I_{rev}\]

(29)#\[G_d=\frac{dI_{vd}}{dU_d}\]

(30)#\[CT=TT \cdot G_d\]

(31)#\[\begin{split}CJ =\begin{cases} CJO(T) \cdot (1-\frac{U_d}{VJ(T)})^{-M}, & \ U_d\leq FC \cdot VJ(T)\\CJO(T) \cdot(1-FC)^{-(1+M)}\cdot(1-FC \cdot(1+M)+M\cdot \frac{U_d}{VJ(T)}),& \ U_d>FC \cdot VJ(T)\end{cases}\end{split}\]

(32)#\[C_d=CT +CJ\]

1. Properties#

Property	Default Value	Description	Units of measurement
RL – leakage resistance	100000.0	–	Ohm
T – diode temperature	25.0	–	℃
AREA - relative area of the diode	1.0E7	–	r.u.
IKF - high-injection knee current	0.0042	–	А
VJ - built-in potential	1.0	–	V
M - grading coefficient	0.5	–	–
IBV - reverse breakdown knee current	1.0E-10	–	А
BV - reverse breakdown knee voltage	1.0E7	–	V
NBV - reverse breakdown ideality	1.0	–	–
IBVL - low-level reverse breakdown current	0.0	–	А
NBVL - low-level reverse breakdown ideality	1.0	–	–
IS - saturation current	1.0E-15	–	А
ISR - recombination current parameter	0.0	–	V
RS - parasitic series resistance	0.0	–	Ohm
N - emission coefficient	1.0	–	–
NR - emission coefficient for ISR	2.0	–	–
CJO - zero-bias junction capacitance	0.0	–	F
TT - transit time	0.0	–	s
FC - forward-bias depletion coefficient	0.5	–	–
Nonlinear dependence of parameters on temperature	Off	–	–
TMEAS - diode temperature when measuring parameters	25.0	–	℃
XTI - temperature exponent for IS, available when selecting `Nonlinear dependence of parameters on temperature` - `On`	3.0	–	–
EG - energy gap, available when selecting `Nonlinear dependence of parameters on temperature` - `On`	1.11	–	eV
TIKF - IKF temperature coefficient (linear), available when selecting `Nonlinear dependence of parameters on temperature` - `On`	0.0	–	–
TBV1 - BV temperature coefficient (linear), available when selecting `Nonlinear dependence of parameters on temperature` - `On`	0.0	–	–
TBV2 - BV temperature coefficient (quadratic), available when selecting `Nonlinear dependence of parameters on temperature` - `On`	0.0	–	–
TRS1 - RS temperature coefficient (linear), available when selecting `Nonlinear dependence of parameters on temperature` - `On`	0.0	–	–
TRS2 - RS temperature coefficient (quadratic), available when selecting `Nonlinear dependence of parameters on temperature` - `On`	0.0	–	–

2. Inputs and outputs#

Parameters	Input/Output	Description	Units of measurement	Port type
Anode	Input	-	-	Electronics
Kathode	Output	-	-	Electronics

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