integrated BJT - inverse characteristics?

[legg]

Discrete BJTs exhibit inverse functional characteristics - some
specific devices are designed to enhance them.

Do integrated BJTs have the same behaviour? Particularly interested in
low Vce/Vec (below a diode drop) and capacitances that may result.

PSpice models don't seem to account for bilateral operation - you seem
to have to add another complete (but lousey) device at the same nodes
to model this function. Inelegant, to say the least.

RL

 

[legg]

Of course they do. What do you think isc, nc, ikr, nr, br, var, etc.,
refer to?

Beware that IC devices have _4_layers_

Some process houses even model that behavior during saturation.

Going to have to look more closely at the documentation. A number of
these parameters typically sport zeros.

Operation is expected within a diode drop of one supply rail or
another. At present I'm concentrating on the negative rail. Still have
no access to process house models. Some progress..eh?

RL

 

[legg]

Of course they do. What do you think isc, nc, ikr, nr, br, var, etc.,
refer to?

.model qn npn
+is=2.209e-17 nf=1.000e+00 vaf=3.119e+01
+bf=1.164e+02 isc=1.820e-16 nc=1.500e+00
+ikf=4.345e-02 ikr=1.560e-02 nr=1.000e+00
+ise=9.490e-16 ne=2.500e+00
+br=1.565e+01 var=2.499e+00
+re=5.268e+00
+rc=2.131e+01
+rb=1.772e+02 trb1=1.000e-03
+rbm=3.167e+01 trm1=1.000e-03
+iss=8.038e-15 ns=1.000e+00
+xcjc=2.000e-01 fc=7.500e-01
+eg=1.110e+00 xti=5.835e+00 xtb=1.078e+00
+tf=9.400e-12 xtf=8.000e+00 itf=4.345e-02
+vtf=1.760e+00 ptf=1.500e+01 tr=1.000e-09
+cje=4.700e-14 mje=4.100e-01 vje=9.600e-01
+cjc=4.300e-14 mjc=3.900e-01 vjc=7.500e-01
+cjs=7.000e-14 mjs=3.900e-01 vjs=5.800e-01
+af=1.900e+00 kf=3.300e-11

Odd.....these parameters give apparent gains of about three orders of
magnitude higher than would be expected, based on straight BF and BR
(+40K and -4K) entries. It also reverses prior to the zero base
current crossing.

This compared to three other models.

RL

 

[legg]

You have to be careful comparing models by amateurs with those from
(us) pros ;-)

BF, for instance, is the beta with no emitter or base current
crowding... NOT what you might measure at IC=1mA

Takes a while to absorb the info in any plot. Looks like all four are
unbelievable nonsense......back to the drawing board.

I'm not trying to design an IC, merely exploring/demonstrating
feasibility, through the modeling linear of interface functions that
can't be readily breadboarded, due to unavailability of the actual
integrated structures.

RL

 

[legg]

Bill Clinton also had a Stimulus Package. Her name was Monica.

I think Bill just had the package. The stimulus was Monica's.