I am reading through the 2003 ARRL Handbook, learning about circuit design,
characteristic curves for common emmitter configuration, load lines and such
things, just about ready to test all this exciting knowledge on a simple
amplifier stage using a 2N2222 transistor and now I can't find the set of
characteristic curves for this transistor ( I actually downloaded the spec
sheet and looked).

Where is this set of curves to be found? Is it not part of a regular spec
sheet for a transistor??

Baffled

Uwe

in article , Ralph Mowery at
wrote on 12/11/03 10:48 PM:

I am reading through the 2003 ARRL Handbook, learning about circuit
design,
characteristic curves for common emmitter configuration, load lines and
such
things, just about ready to test all this exciting knowledge on a simple
amplifier stage using a 2N2222 transistor and now I can't find the set of
characteristic curves for this transistor ( I actually downloaded the spec
sheet and looked).

Where is this set of curves to be found? Is it not part of a regular spec
sheet for a transistor??

Baffled

Uwe

Here is a curve for the 2n2222.

http://hibp.ecse.rpi.edu/~connor/edu..._3_Transistors.
pdf

http://hyperphysics.phy-astr.gsu.edu.../loadline.html


Go about 3/4 the way down the page.

The curves are in many books the manufactors publish.





Great info, thanks Uwe

in article , Ralph Mowery at
wrote on 12/11/03 10:48 PM:

I am reading through the 2003 ARRL Handbook, learning about circuit
design,
characteristic curves for common emmitter configuration, load lines and
such
things, just about ready to test all this exciting knowledge on a simple
amplifier stage using a 2N2222 transistor and now I can't find the set of
characteristic curves for this transistor ( I actually downloaded the spec
sheet and looked).

Where is this set of curves to be found? Is it not part of a regular spec
sheet for a transistor??

Baffled

Uwe

Here is a curve for the 2n2222.

http://hibp.ecse.rpi.edu/~connor/edu..._3_Transistors.
pdf

http://hyperphysics.phy-astr.gsu.edu.../loadline.html


Go about 3/4 the way down the page.

The curves are in many books the manufactors publish.





Great info, thanks Uwe

I am reading through the 2003 ARRL Handbook, learning about circuit
design,
characteristic curves for common emmitter configuration, load lines and
such
things, just about ready to test all this exciting knowledge on a simple
amplifier stage using a 2N2222 transistor and now I can't find the set of
characteristic curves for this transistor ( I actually downloaded the spec
sheet and looked).

Where is this set of curves to be found? Is it not part of a regular spec
sheet for a transistor??

Baffled

Uwe

Here is a curve for the 2n2222.

http://hibp.ecse.rpi.edu/~connor/edu...ransistors.pdf

http://hyperphysics.phy-astr.gsu.edu.../loadline.html


Go about 3/4 the way down the page.

The curves are in many books the manufactors publish.

I am reading through the 2003 ARRL Handbook, learning about circuit
design,
characteristic curves for common emmitter configuration, load lines and
such
things, just about ready to test all this exciting knowledge on a simple
amplifier stage using a 2N2222 transistor and now I can't find the set of
characteristic curves for this transistor ( I actually downloaded the spec
sheet and looked).

Where is this set of curves to be found? Is it not part of a regular spec
sheet for a transistor??

Baffled

Uwe

Here is a curve for the 2n2222.

http://hibp.ecse.rpi.edu/~connor/edu...ransistors.pdf

http://hyperphysics.phy-astr.gsu.edu.../loadline.html


Go about 3/4 the way down the page.

The curves are in many books the manufactors publish.

In article , Uwe Langmesser
writes:

I am reading through the 2003 ARRL Handbook, learning about circuit design,
characteristic curves for common emmitter configuration, load lines and such
things, just about ready to test all this exciting knowledge on a simple
amplifier stage using a 2N2222 transistor and now I can't find the set of
characteristic curves for this transistor ( I actually downloaded the spec
sheet and looked).

Where is this set of curves to be found? Is it not part of a regular spec
sheet for a transistor??

Baffled

The two links provided by Ralph Mowrey are good ones and the first
has an "approximate" set of curves for the good old 2N2222.

Contrary to what Ralph said, manufacturers seldom publish
collector-v-base curves now because few designers use such
information. Silicon BJTs are so nice and straight-line-ish on
the common-emitter collector graphs that it isn't needed. The
only non-linear part is at very low collector-emitter voltages but
that is almost a given and the same for every transistor.

Vacuum tube internal geometry variations created the variations in
"plate curves" along with the different types of pentodes: Sharp
cutoff, remote cutoff, etc. Positioning of the electrodes in the
electron stream and their interaction with each other created the
different curves. With transistor junctions the only variation is the
low V_sub_CE and low base current...which can generally be
graphed by hand from a variable bench supply without blowing up the
device. In trying to create one's own curves at high V_sub_CE, a
pulsed supply MUST be used or the transistor dissipation ratings are
exceeded.

If you are going to present a low-resistance DC load to a transistor
driver but the load is a medium-impedance at RF, the collector
current is chosen from two main factors: (1) Small-signal h_sub_fe
(which can vary from lot to lot and sometimes has its own curves);
(2) Collector-emitter junction dissipation (it's the full V_sub_CC times
the collector current at DC). That holds at AF as well as RF if the
circuit is a transformer-coupled amplifier.

If you are doing something like a "resistance-coupled" amplifier, then
you can trust the curves to be nice and straight and set the "load
line" center point by arithmetic. Voltage across the load resistor is
the same at DC as at AF or RF...but the LOAD impedance of the
driven stage is going to be in parallel with that resistor...plus the
h_sub_oe (internal resistance of the collector-emitter junction)
at AF or RF.

FETs are the closest active device to vacuum tubes. Very high
input impedance, drain voltage signal variation a function of trans-
conductance times total load impedance. A no-sweat calculation.
Bipolars are another story and gain of bipolar stages MUST be
calculated in terms of power out v. power in due to the base
current being the input. Bipolar Junction Transistors (BJTs) have
to be thought of as different from vacuum tubes' design rules.

As you go into frequencies approaching the "transition frequency"
or f_sub_t, there's a whole potfull of new and different curves for
BJTs that tubes never had. Those ARE published on BJTs designed
for RF work; to use them properly, you must also know complex
number quantities and admittance-impedance transformations (not
hard at all with a good scientific calculator).

For applications at frequencies below about 1/20th of the f_sub_t,
no problem on not using collector-v-base-current curves. You will
find that there might be some small-signal current gain variation at
different collector currents and some BJTs might have curves for
that. Load lines with BJTs in linear amplifier circuits gets a bit
unneccessary.

Len Anderson
retired (from regular hours) electronic engineer person

In article , Uwe Langmesser
writes:

I am reading through the 2003 ARRL Handbook, learning about circuit design,
characteristic curves for common emmitter configuration, load lines and such
things, just about ready to test all this exciting knowledge on a simple
amplifier stage using a 2N2222 transistor and now I can't find the set of
characteristic curves for this transistor ( I actually downloaded the spec
sheet and looked).

Where is this set of curves to be found? Is it not part of a regular spec
sheet for a transistor??

Baffled

The two links provided by Ralph Mowrey are good ones and the first
has an "approximate" set of curves for the good old 2N2222.

Contrary to what Ralph said, manufacturers seldom publish
collector-v-base curves now because few designers use such
information. Silicon BJTs are so nice and straight-line-ish on
the common-emitter collector graphs that it isn't needed. The
only non-linear part is at very low collector-emitter voltages but
that is almost a given and the same for every transistor.

Vacuum tube internal geometry variations created the variations in
"plate curves" along with the different types of pentodes: Sharp
cutoff, remote cutoff, etc. Positioning of the electrodes in the
electron stream and their interaction with each other created the
different curves. With transistor junctions the only variation is the
low V_sub_CE and low base current...which can generally be
graphed by hand from a variable bench supply without blowing up the
device. In trying to create one's own curves at high V_sub_CE, a
pulsed supply MUST be used or the transistor dissipation ratings are
exceeded.

If you are going to present a low-resistance DC load to a transistor
driver but the load is a medium-impedance at RF, the collector
current is chosen from two main factors: (1) Small-signal h_sub_fe
(which can vary from lot to lot and sometimes has its own curves);
(2) Collector-emitter junction dissipation (it's the full V_sub_CC times
the collector current at DC). That holds at AF as well as RF if the
circuit is a transformer-coupled amplifier.

If you are doing something like a "resistance-coupled" amplifier, then
you can trust the curves to be nice and straight and set the "load
line" center point by arithmetic. Voltage across the load resistor is
the same at DC as at AF or RF...but the LOAD impedance of the
driven stage is going to be in parallel with that resistor...plus the
h_sub_oe (internal resistance of the collector-emitter junction)
at AF or RF.

FETs are the closest active device to vacuum tubes. Very high
input impedance, drain voltage signal variation a function of trans-
conductance times total load impedance. A no-sweat calculation.
Bipolars are another story and gain of bipolar stages MUST be
calculated in terms of power out v. power in due to the base
current being the input. Bipolar Junction Transistors (BJTs) have
to be thought of as different from vacuum tubes' design rules.

As you go into frequencies approaching the "transition frequency"
or f_sub_t, there's a whole potfull of new and different curves for
BJTs that tubes never had. Those ARE published on BJTs designed
for RF work; to use them properly, you must also know complex
number quantities and admittance-impedance transformations (not
hard at all with a good scientific calculator).

For applications at frequencies below about 1/20th of the f_sub_t,
no problem on not using collector-v-base-current curves. You will
find that there might be some small-signal current gain variation at
different collector currents and some BJTs might have curves for
that. Load lines with BJTs in linear amplifier circuits gets a bit
unneccessary.

Len Anderson
retired (from regular hours) electronic engineer person