#1615 MHQ6002 Quad Complementary Transistors

Episode 1615 chip of the day
true complementary devices

[ats]

Watching this brought back an old war story...

Navy submarines used to have a roll of toilet paper mounted on each of the displays. It was fun to ask random people what the toilet paper was for. Very few realized it was to erase grease pencil marks...

[ketv]

Back in the day, it was pretty common to use one pair as a heater and temperature sensor, so that the second pair were held at a constant temperature. That way the kT/q dependency was taken out of the equation.

[Homer]

Always feel good about myself when I use complementary transistors 👍

[joseppuig]

I think manufacturers call then complementary when they share very similar limits in their specs such as voltage, current, power dissipation, frequency limit, and internal capacitances.
Another thing is "matched" where they behave identical in their way of working, and that's what you see on the curce tracer.

[tedivester]

Well it's back in the day - time again! We used to go through a bag of transistors testing for balance when using them in differential amplifiers. I really loved Tektronix curve tracers.

[MsFireboy]

Awe matched transistors in one package. This would be useful in the construction of differential amplifier circuits. Thanks for sharing.

[Hellhound]

For matching small transistors, I use my analog discovery 2 with the transistor-attachment… you can store reference traces and compare them. But those old-school stuff just have so much charm to them.

[edgeeffect]

Now I've gotta get myself a whiteboard marker.

[d.jeffdionne]

I was surprised the Early voltage is so low on that 2N3906... so I looked at the data sheet and didn't see it specified. But Mot, er, OnSemi has SPICE models for each. And, behold! VAF is only 156 for 2N3906, and 1000 (that means 'large') for 3904. I'm a bit lazy to take the time to actually run curves in SPICE3, but it would be interesting to see how well they match the sample (of one) that you ran on the tracer.

[AnalogDude_]

These are the harris, Intersil replacement parts from Renesas: HFA3046, HFA3096, HFA3127, HFA3128, Analog Devices also has a few.
How would these perform?

[ThermalWorld_]

Thanks.. I learned something new today 😄

[andymouse]

I wonder why, as has been commented on that we don't see theses used in preamps and stuff where you might want a Current mirror and a differential amplifier all in one place and thermally coupled and matched and all that good stuff ? fascinating !...cheers. love chip of the day.

[ivolol]

If you took ~8 2907s and ~8 2222s, did a quick'n'dirty measure of their betas, then took the best matched pair, I wonder how well matched they'd come out in the curve tracer?

[alklapaxida]

i thought "complementary transistors" were when you walked in the store and they gave them to you free of charge . . .

[jtabet]

Love your videos, can you create one explaining how a curve tracer works

[Science-Vlog]

Experienced people like you, filled with knowledge, a treasurefor young generations to follow but no they are lost in distractions.

[bayareapianist]

I have a good reason for those of you who wondered why these chips are obsolete. But I won't give it away until you guys tell me what you think. A few hints... 1) it is not the cost of the manufacturing. 2) something else replace these and people never look back at them. 3) say what replaced them?

[bayareapianist]

Can you do a chip of the day for CD4007? Is there any analog use for it?

[robertbox]

We used a thing called BCV62 super matched pair. If it got heated by the PCB it would drift all over.

[nickcaruso]

complementary just means n and p, matched characteristics is additional trait, right?