Episode 1176 chip of the day NPN transistor package Be a Patron: / imsaiguy
Пікірлер: 43
@GabeWachob2 жыл бұрын
50 ma max collector current… it’s noted before the tables of electrical characteristics… I was shouting “look further up in the page!” while watching…
@GabeWachob2 жыл бұрын
Under absolute maximum ratings….
@paulbishop10162 жыл бұрын
Perhaps 50ma is the total device collector current so 10ma/transistor?? Not clear.
@RexxSchneider Жыл бұрын
@@paulbishop1016 An "absolute maximum" rating is one that should never be exceeded to avoid the possibility of damage to the device. So the recommended operating conditions always have some margin to ensure you never exceed it. If the absolute maximum collector current were 10mA, you'd never see the hFE at 10mA specified on the datasheet. It's a pretty safe bet that 50mA per transistor is the absolute maximum collector current. Of course, the maximum usable working collector current may also be limited by the absolute maximum dissipation of 300mW per transistor, e.g. 20mA per device at 15V supply.
@alexlo77082 жыл бұрын
Collective current might not well defined because it is variably from whether you have heatsink or not.
@Enigma7582 жыл бұрын
It seems as thought that chip was made for your circuit!
@TheTubeDude2 жыл бұрын
Hi, Please tell me what oscilloscope (Rigol) model you are using. Thank you very much.
@IMSAIGuy2 жыл бұрын
kzbin.info/www/bejne/m5LSeYyNjrGFjJI
@RexxSchneider2 жыл бұрын
If you're looking for maximum collector current, you really ought to be looking at the section "Absolute Maximum Ratings" (see 2:07 ) where you'll find that Ic max is 50mA and Vce max = 15V. It's really worth rehearsing the parameters you're going to talk about _before_ you start making the video.
@curtperry41342 жыл бұрын
Shouldn't the emitter of the emitter follower be connected to -V and not ground? Otherwise the signal will clip since it is oscillating around zero volts. Or am I missing something?
@fabiotrevisan89222 жыл бұрын
Ideally yes, to be fully on the conservative side, but not really in this example, as one of the inputs of the amplifier is referenced to ground and the collector of that transistor can only go down to about 0.6V anyway. Hooking up the emitter follower to ground, instead of -V in this case may lighten the dissipated power on the lil' thing. By the way, despite the Max IC is 50mA, the device Max Power is just 300mW, so it's quite unlikely that anyone would run those transistors at much more than 5mA each.
@RexxSchneider Жыл бұрын
The output from either collector will have a quiescent bias point around (+V)/2, so there's no point in connecting an emitter follower to (-V), as it will clip on the positive excursion anyway as soon as the output approaches ±(+V)/2. This assumes that the supply rails are symmetrical. If the biasing isn't obvious, take an example where the supply is ±12V. Looking at the circuit at 6:01 the current mirror sinks (12V - 0.65V) / 18K = 0.63mA into pin 11. So ideally, 0.63mA is also sunk into pin 14. If the input voltage at pin 2 equals the voltage at pin 4 (i.e. 0V), then the current ideally splits equally between the differential pair, and there is 0.315mA through each. The quiescent voltage across each output resistor is then 0.315mA x 18K = 5.67V, and therefore each collector is biased to 12V - 5.67V = 6.33V above ground. The maximum symmetrical output swing is about ±5.6V before clipping and the output never reaches ground.
@RexxSchneider Жыл бұрын
@@fabiotrevisan8922 That's pretty much the right way to think about the circuit, although the dissipation in the emitter follower would be independent of whether its emitter resistor is connected to ground or to (-V). The power dissipated in the emitter resistor would, of course, be different. Incidentally, a lot of the parameters and graphs given in the datasheet are specified at Ic = 1mA and Vce = 3V, so I'd aim for somewhere near that when designing in the absence of other constraints.
@VoidHalo11 ай бұрын
I have some CA3086s, which just have 3 NPN and 2 PNP transistors. These would be really nifty as I've been exploring diff amps lately. There is also the CA3096, which is configured for a diff amp, but in a slightly different way. Makes me think I need to find a comprehensive list of CA series chips.
@SouthShoreSonics7 күн бұрын
If you are interested I can send you a CA3081 RCA 1973 chip for your "chip of the day".
@stamasd85002 жыл бұрын
I've used the CA3046 in the past to make custom amplifiers. As well as some of its brethren like CA3096 (5 independent NPN transistors) and CA3054 (two full differential amplifiers). I particularly liked the 3054, it has almost everything one needs to make an instrumentation amplifier. And yes, the parts were originally developed by RCA (thus the "CA" in the part number).
@chrisengland55232 жыл бұрын
The maximum collector current for the CA3046 is 50mA. It's right at the top of page 2 of the data sheet under the heading "Absolute Maximum Ratings", where you would expect to find it.
@IMSAIGuy2 жыл бұрын
you are late to the party, many viewer have already chastised me for that
@bradandrews78232 жыл бұрын
The classic 'Tandem Match' by John Grebenkemper (then KA3BLO - July 1987 QST) used the CA3146 (higher voltage version of 3046) as log/antilog amplifiers to compute and directly display SWR from voltages obtained from forward and reflected power detectors. I believe the circuit topology was called a 'Gilbert Cell'. I adapted the design for some homebrew RF power metering projects of my own. It worked well.
@urlkrueger2 жыл бұрын
OK, I'll take a hundred. Don't know for sure what I'll do with them but maybe they would come in handy in circuit to charge my fluxcapacitor or in a planetary force field detector.
@aduedc2 жыл бұрын
Thanks I was looking for such transistor arrays (HFA3046, HFA3096, HFA3127, HFA3128)I am designing I am designing two stage cascading common emitter amplifier which are "DC Coupled" to find out resonant frequency of capacitors. I see many circuits in the industry , which are fairly high in frequency, and are AC coupled. The capacitor needed to couple these stages are specified, but such capacitors have resonant frequency less than the frequency of the circuit! One such circuit I see quit often is common emitter amplifier with emitter bias resistor shunted to ground with a large cap! The cap of such value has self resonant frequency of much less than operating frequency of the circuit!!!
@robertneill30572 жыл бұрын
Any amplifier has an operating frequency bandwidth which in turn has an influence on the capacitor values selected. Usually this is the lowest frequency the amplifier has to handle in as far as capacitor selection is concerned.
@AnalogDude_2 жыл бұрын
Use That300, That320 or That340 from the That cooperation and a tiny bit cheaper, the HFA parts are design for high frequencies. 8GHz for npn and 5.5 gHz for pnp.
@mikemines29312 жыл бұрын
Made great IF amps still got a few stashed now like hens teeth
@soroushzarein3246 Жыл бұрын
Please share a video about power electronic
@100amps2 жыл бұрын
I've always stuggled to grasp how the input diff amp in a solid state audio amplifier works, and this kinda helped, but not too much. You skimmed over the details too much for my pea brain to fill in the gaps. I'd like to understand the constant current source and current mirror better too. A deeper dive is requested.
@IMSAIGuy2 жыл бұрын
try this series: kzbin.info/www/bejne/kGmtdaasm7-dgpo
@kabandajamir98442 жыл бұрын
The world's best teacher
@__--JY-Moe--__2 жыл бұрын
PPPPP -->>PiPiPiPiPi....this was so far back in time, probably has 5 grains of sand inside!! ha..ha...
@Dennis-uc2gm2 жыл бұрын
I have a few NOS RCA's in some of that black conductive foam all stuck to the legs🙂
@waverlyarbeau49622 жыл бұрын
Marshall used it for switching the distortion and reverb on and off in some of their old amps.
@davidharms35622 жыл бұрын
Great video! Thanks!
@t1d1002 жыл бұрын
Nice chip. Thanks.
@erikr0072 жыл бұрын
Hi! I like the track layout of the "Digital Proto Boards" that you use. Where can you get them?