Micro-Cap v7.1.6 / RM
.PDFModel parameters for level 8 (continued)
Name |
Parameter |
Default |
WELM |
Width dependence of ELM |
0.00 |
PELM |
Length and width product dependence of ELM |
0.00 |
WL |
Coefficient for length dependence of width offset |
0.00 |
WLN |
Power of length dependence of width offset |
1.00 |
WW |
Coefficient for width dependence of width offset |
0.00 |
WWN |
Power of width dependence of width offset |
1.00 |
WWL |
Coeff. of len. and width cross term for width off. |
0.00 |
LL |
Coefficient for length dependence for length offset |
0.00 |
LLN |
Power of length dependence for length offset |
1.00 |
LW |
Coefficient for width dependence for length offset |
0.00 |
LWN |
Power of width dependence for length offset |
1.00 |
LWL |
Coeff. of length and width cross term for length offset |
0.00 |
TNOM |
Temperature at which parameters are extracted |
27.00 |
UTE |
Mobility temperature exponent |
-1.50 |
LUTE |
Length dependence of UTE |
0.00 |
WUTE |
Width dependence of UTE |
0.00 |
PUTE |
Length and width product dependence of UTE |
0.00 |
KT1 |
Temperature coefficient for threshold voltage |
-0.11 |
LKT1 |
Length dependence of KT1 |
0.00 |
WKT1 |
Width dependence of KT1 |
0.00 |
PKT1 |
Length and width product dependence of KT1 |
0.00 |
KT1L |
Channel length sensitivity of temperature |
|
|
coefficient for threshold voltage |
0.00 |
LKT1L |
Length dependence of KT1L |
0.00 |
WKT1L |
Width dependence of KT1L |
0.00 |
PKT1L |
Length and width product dependence of KT1L |
0.00 |
KT2 |
Body bias coefficient of the threshold |
|
|
voltage temperature effect |
0.022 |
LKT2 |
Length dependence of KT2 |
0.00 |
WKT2 |
Width dependence of KT2 |
0.00 |
PKT2 |
Length and width product dependence of KT2 |
0.00 |
UA1 |
Temperature coefficient for UA |
4.31E-9 |
LUA1 |
Length dependence of UA1 |
0.00 |
WUA1 |
Width dependence of UA1 |
0.00 |
PUA1 |
Length and width product dependence of UA1 |
0.00 |
UB1 |
Temperature coefficient for UB |
-7.61E-18 |
LUB1 |
Length dependence of UB1 |
0.00 |
WUB1 |
Width dependence of UB1 |
0.00 |
448 Chapter 22: Analog Devices
Model parameters for level 8 (continued)
Name |
Parameter |
Default |
WNSUB |
Width dependence of NSUB |
0.00 |
PNSUB |
Length and width product dependence of NSUB |
0.00 |
VBX |
VBS at which the depletion width equals XT |
0.00 |
LVBX |
Length dependence of VBX |
0.00 |
WVBX |
Width dependence of VBX |
0.00 |
PVBX |
Length and width product dependence of VBX |
0.00 |
VBM |
Maximum applied body bias in Vth calculation |
0.00 |
LVBM |
Length dependence of VBM |
0.00 |
WVBM |
Width dependence of VBM |
0.00 |
PVBM |
Length and width product dependence of VBM |
0.00 |
XT |
Doping depth |
0.00 |
LXT |
Length dependence of XT |
0.00 |
WXT |
Width dependence of XT |
0.00 |
PXT |
Length and width product dependence of XT |
0.00 |
JSSW |
Bulk p-n sidewall saturation current density |
0.00 |
Noise equations
Noise models for the BSIM3 device are defined in reference 22 at the beginning of this chapter and are used when NLEV is undefined. Noise models for all cases are as follows:
Parasitic lead resistor thermal noise
I2 |
= 4•k•T / RG |
|
|
I2rd |
= 4•k•T / RD |
|
|
I2rs |
= 4•k•T / RS |
|
|
I2rb |
= 4•k•T / RB |
|
|
Channel and shot flicker noise |
|||
Ichannel2 = Ishot2 + Iflicker2 |
|
||
Intrinsic flicker noise: |
Iflicker2 |
= KF•IdrainAF / ( COX • Leff2 • f ) |
|
If NLEV = 0 |
|||
If NLEV = 1 |
Iflicker2 |
= KF•IdrainAF / ( COX • Weff • Leff • f ) |
|
If NLEV = 2 or 3 |
Iflicker2 |
= KF•IdrainAF / ( COX • Weff • Leff • fAF ) |
|
Intrinsic shot noise:
If NLEV < 3 Ishot2 = (8/3)•k•T•gm
If NLEV = 3 Ishot2 = GDSNOI•(8/3)•k•T•gm•beta•(Vgs-Vth)•(1+a+a2)/(1+a) a = 1 - Vds/Vdsat if Vds <= Vdsat (linear region) and a = 0 elsewhere.
450 Chapter 22: Analog Devices
OPAMP
Schematic format
PART attribute <name>
Examples
OP1
MODEL attribute <model name>
Example
LF351
There are three model levels for the OPAMP. Each succeeding level provides increasingly more realistic models at the expense of increasingly more complex equivalent circuits.
Level 1 is a simple voltage-controlled current source with a finite output resistance and open loop gain.
Level 2 is a three stage, two pole model with slew rate limiting, finite gain, and output resistance.
Level 3 is an enhanced Boyle model, similar to those implemented in other SPICE programs as subcircuits. It is not, however, a macro or a subcircuit, but a fully internal MC7 device model. It models positive and negative slew rates, finite gain, AC and DC output resistance, input offset voltage and current, phase margin, common mode rejection, unity gain bandwidth, three types of differential input, and realistic output voltage and current limiting.
Model statement forms
.MODEL <model name> OPA ([model parameters])
Examples
.MODEL LM709 OPA (A=45K VOFF=.001 SRP=250K GBW=1E6)
.MODEL LF155 OPA (LEVEL=2 TYPE=1 A=50K SRP=330K)
451
Temperature effects
Temperature affects diodes, BJTs, and JFETs in the usual way as described in the model sections for these devices. Default temperature parameters are used.
Level 1 equations
R = ROUTAC+ROUTDC
GM = A/R
Level 2 equations
R = ROUTAC+ROUTDC
GM = A1/3/ R
F1 = First pole = GBW/A
U= .5•A•Sin(PM)
V= (1+A•Cos(PM))/(U•U)
F0 = Unity gain frequency = F1•U•(1+sqrt(1-V))
F2 = Second pole = F0/(U•(1-sqrt(1-V)))
C1 = 1/(2•π •F1•R)
C2 = 1/(2•π •F2•R)
Level 3 equations
RC1 = 1/(2•π •GBW•C2)
RC2 = RC1
F1 = First pole = GBW/A
U= .5•A•Sin(PM)
V= (1+A•Cos(PM))/(U•U)
F0 = Unity gain frequency = F1•U•(1+sqrt(1-V))
F2 = Second pole = F0/(U•(1-sqrt(1-V)))
C1 = 0.5/(2•π •F2•RC1)
C2 = C
R2 = 1E5
GA = 1/RC1
VAF = 200
NPN and PNP input stages
NPN input
IC1 = SRP•C2/2
CE = 2•IC1/SRN-C2
PNP input
IC1 = SRN•C2/2
CE = 2•IC1/SRP-C2
BETA1 = IC1/(IBIAS+IOFF/2)
456 Chapter 22: Analog Devices