Compact MOS-Transistor Model (mos705)

The mos705 model is a compact MOS-transistor model, intended for the simulation of circuit behavior with emphasis on analog applications. It is described in the Philips MOST Modelbook (Dec.93) as MOS model, level 705.

In extension to the model book description a minimum conductance gmin is inserted between the drain and source node, to aid convergence. The value of gmin is set by an options statement, default = 1e-12 S.

This device is supported within altergroups.

This device is dynamically loaded from the shared object /<install_dir>/tools.lnx86/cmi/lib/5.0/libphilips_sh.so.

Sample Instance Statement:

mn1 (1 2 0 0) mna7 ln=120e-6 wn=12e-6

Sample Model Statement:

model mna7 mos705 type=n vtn=0.853 betan=77e-6 tox=15e-9 vfb=-850e-3 tref=25 subthn=3 phi=0.645 lap=100e-9 gkn=-350e-9 th1n=0.15 th2n=0.046 th3n=0.1 fnoise=1e-10

Instance Syntax

Name  d  g  s  [b] ModelName parameter=value ...

Instance Parameters

`wn=1.0 scale m`	Drawn channel width in the lay-out of the actual transistor. Scale set by option scale.
`ln=1.0 scale m`	Drawn channel length in the lay-out of the actual transistor. Scale set by option scale.
`w=1.0 scale m`	Alias for `wn`.
`l=1.0 scale m`	Alias for `ln`.
`mult=1`	Number of devices in parallel.
`area=1`	Alias of `mult`.
`region=triode`	Estimated DC operating region, used as a convergence aid. Possible values are `off`, `triode`, `sat`, or `subth`.
`m=1`	Multiplicity factor.
`trise=0 K`	Temperature rise from ambient.

Model Syntax

model modelName mos705 parameter=value ...

Model Parameters

`type=n`	Transistor gender. Possible values are `n` or `p`.
`vtn=0 V`	Threshold voltage of the reference transistor at the reference temperature.
`kon=0` √`V`	`Ko` of the reference transistor.
`kn=100m` √`V`	`K` of the reference transistor.
`vsbxn=0 V`	`Vsbx` of the reference transistor.
`delvx=0 V`	`Dvsbx` of the reference transistor.
`th1n=0 1/V`	`The1` of the reference transistor.
`th2n=0 1/`√`V`	`The2` of the reference transistor.
`th3n=0 1/V`	`The3` of the reference transistor at the reference temperature.
`gamman=0`	`Gam` of the reference transistor.
`shiftn=0 V^(1-n)`	`Sh` of the reference transistor.
`nn=0`	`N` of the reference transistor.
`pn=0 1/V`	`P` of the reference transistor.
`ava=0`	`A` of the reference transistor.
`avb=1 V`	`B` of the reference transistor.
`avc=0`	`C` of the reference transistor.
`wref=100u m`	Effective width of the reference transistor.
`wtol=0 m`	Difference between drawn and effective gate width.
`dvtn=0 V m`	Narrow-width factor of the threshold voltage at `vsbref`.
`dkon=0` √`v m`	Narrow-width factor of `ko`.
`dkn=0` √`v m`	Narrow-width factor of `k`.
`dvsbxn=0 V m`	Narrow-width factor of `vsbx`.
`ddelvx=0 Vm`	Narrow-width factor of `dvsbx`.
`betan=20u A/V`²	Gain factor of a infinite-square transistor at the reference temperature.
`dth1n=0 m/V`	Narrow-width factor of `the1`.
`dth2n=0 m/`√`V`	Narrow-width factor of `the2`.
`dth3n=0 m/V`	Narrow-width factor of `the3`.
`dgamn=0 m`	Narrow-width factor of `gam`.
`dava=0 m`	Narrow-width factor of `a`.
`davb=0 V m`	Narrow-width factor of `b`.
`davc=0 m`	Narrow-width factor of `c`.
`lref=100u m`	Effective length of the reference transistor.
`ltol=0 m`	Difference between drawn and actual gate polysilicon length.
`gvtn=0 V m`	Short-channel factor of the threshold voltage at `vsbref`.
`gkon=0` √`V m`	Short-channel factor of `ko`.
`gkn=0` √`V m`	Short-channel factor of `k`.
`gvsbxn=0 V m`	Short-channel factor of `vsbx`.
`gdelvx=0 V m`	Short-channel factor of `dvsbx`.
`gth1n=0 m/V`	Short-channel factor of `the1`.
`gth2n=0 m/`√`V`	Short-channel factor of `the2`.
`gth3n=0 m/V`	Short-channel factor of `the3`.
`ggamn=0 m`	Short-channel factor of `gam`.
`gshift=0 V^(1-n) m`²
	Short-channel factor of `sh`.
`gnn=0 m`	Short-channel factor of `n`.
`gpn=0 m/V`	Short-channel factor of `p`.
`gava=0 m`	Short-channel factor of `a`.
`gavb=0 V m`	Short-channel factor of `b`.
`gavc=0 m`	Short-channel factor of `c`.
`lap=0 m`	Half of the effective channel-length reduction due to lateral diffusion.
`vsbref=0 V`	Source to bulk reference voltage for parameter determination.
`phi=600m V`	Diffusion potential at the reference temperature.
`tcvt=-1m V/K`	Temperature coefficient of `vto`.
`tbetan=1.5`	Power temperature coefficient of `bet`.
`tth3n=0 1/(V K)`	Temperature coefficient of `the3`.
`tgth3n=0 m/(V K)`	Temperature coefficient of the length dependence of `the3`.
`m=1.0`	Subthreshold-slope factor at reference back bias and at the reference temperature.
`subthn=0`	Weak-inversion factor.
`vtr=0 V`	Depletion-MOS-transistor-transition voltage.
`ratio=0`	Depletion-MOS-transistor-gain ratio.
`vfb=0 V`	Flat-band voltage.
`tox=100n m`	Gate-oxide thickness.
`col=0 F/m`	Gate/drain or gate/source overlap capacitance per unit length.
`fnoise=0 m`² `V`²	Flicker-noise factor.
`tnoise=0`	Thermal-noise factor.

Temperature parameters

`tr (C)`	Reference temperature. Default set by option `tnom`.
`tref (C)`	Alias of `tr`. Default set by option `tnom`.
`tnom (C)`	Alias of `tr`. Default set by option `tnom`.
`dta=0 K`	Deviation between the temperature of the transistor and the temperature of the circuit.
`trise=0 K`	Alias of `dta`.

Output Parameters

`weff (V)`	Effective channel width of the actual transistor.
`leff (V)`	Effective channel length of the actual transistor.
`twophif (V)`	Diffusion potential.
`bet (A/V`²`)`	Gain factor of the transistor.
`k (`√`V )`	Body-effect factor.
`ko (`√`V )`	Initial body-effect factor for dual `k` approach.
`vsbx (V)`	Transition voltage for dual `k` approach.
`dvsbx (V)`	Transition-voltage range for dual `K` approach.
`vto (V)`	Threshold voltage.
`von (V)`	Onset voltage of the superthreshold region.
`the1 (1/V)`	Gate-bias-controlled transverse-field mobility reduction factor.
`the2 (1/`√`V )`	Back-bias-controlled transverse-field mobility reduction factor.
`the3 (1/V)`	Lateral-field mobility reduction factor (velocity saturation).
`gam`	Static-drain-feedback factor.
`sh (V^(1-n))`	Threshold-voltage-shift factor.
`n`	Threshold-voltage-shift exponent.
`p (1/V)`	Back-bias-shift factor.
`me (`√`V )`	Auxiliary parameter for subthreshold-slope factor.
`a`	Weak-avalanche multiplier.
`b (V)`	Weak-avalanche exponent factor.
`c`	Saturation-voltage reduction factor.
`cox (F)`	Gate capacitance.
`cgso (F)`	Gate/source-overlap capacitance.
`cgdo (F)`	Gate/drain-overlap capacitance.
`vtre (V)`	Depletion MOS transistor transition voltage.
`ratio`	Depletion MOS transistor gain ratio.
`vfbe (V)`	Flat band voltage.
`vtemp (V)`	kT/q at actual device temperature.
`gnoise (V`²`)`	Coefficient of the flicker noise for the actual transistor.
`unoise (J)`	Coefficient of the thermal noise for the actual transistor.

Operating-Point Parameters

`ide (A)`	Drain current.
`ige (A)`	Gate current.
`ise (A)`	Source current.
`ibe (A)`	Bulk current.
`vds (V)`	Drain-source voltage.
`vgs (V)`	Gate-source voltage.
`vsb (V)`	Source-bulk voltage.
`ids (A)`	Drain-source current.
`idb (A)`	Drain-bulk current.
`isb (A)`	Source-bulk current.
`pwr (W)`	Power.
`vts (V)`	Vto including back-bias effects.
`vgt (V)`	Effective gate drive including back-bias and drain effects.
`vdss (V)`	Saturation voltage at actual bias.
`gm (S)`	Transconductance (d ids / d vgs).
`gmb (S)`	Bulk transconductance (d ids / d vbs).
`gds (S)`	Output conductance (d ids / d vds).
`cdd (F)`	Capacitance (d qd / d vd).
`cdg (F)`	Capacitance (- d qd / d vg).
`cds (F)`	Capacitance (- d qd / d vs).
`cdb (F)`	Capacitance (- d qd / d vb).
`cgd (F)`	Capacitance (- d qg / d vd).
`cgg (F)`	Capacitance (d qg / d vg).
`cgs (F)`	Capacitance (- d qg / d vs).
`cgb (F)`	Capacitance (- d qg / d vb).
`csd (F)`	Capacitance (- d qs / d vd).
`csg (F)`	Capacitance (- d qs / d vg).
`css (F)`	Capacitance (d qs / d vs).
`csb (F)`	Capacitance (- d qs / d vb).
`cbd (F)`	Capacitance (- d qb / d vd).
`cbg (F)`	Capacitance (- d qb / d vg).
`cbs (F)`	Capacitance (- d qb / d vs).
`cbb (F)`	Capacitance (d qb / d vb).
`u`	Transistor gain (gm/gds).
`rout (`Ω`)`	Small signal output resistance (1/gds).
`vearly (V)`	Equivalent Early voltage (\|Id\|/gds).
`keff (`√`V )`	Describes body effect at actual bias.
`beff (S/V)`	Effective beta at actual bias in the simple MOS model.
`fug (Hz)`	Unity gain frequency at actual bias (gm/(2picox)).
`sqrtsfw (V/`√`Hz )`
	Input-referred RMS white noise voltage (sqrt(sth)/gm).
`sqrtsff (V/`√`Hz )`
	Input-referred RMS 1/f noise voltage at 1kHz (sqrt(gnoise/1000)).
`fknee (Hz)`	Cross-over frequency above which white noise is dominant.

Spectre Circuit Simulator Components and Device Models Reference
Product Version 23.1, June 2023