Questions about Transistors with high beta (hfe) up to 3000 without Darl.-Topology
Single transistors (i. e. without internal darlington topology) with very high hfe up to 3000 are not often to find.
Here some examples:
NEC 2SC3622 - 2SC3624 (1000-3200)
Sanyo 2SC3689 (800-3200) / 2SA1434 (500-1200)
Which benefits are there in opposite to a darlington topology?
Are there particularly suited for certainly amplifier topologies?
Which certain applications are there, where normal darlingtons are not a good choice?
Thank you for comments.
Interesting. These are like the "super-beta" devices found in some old opamps.
They were obviously specced for switching as the current does not go below 10mA in the gain graphs. You get high beta by having a very thin base, which gives low Vceo
The ft is good compared with a darlington and saturation voltage is much lower
Ill add some to that list in a day or two.
High voltage ones are available, I use them in inputstages and in beta enhanced vas sometimes.
Great for input LTP s as it improves DC offset problems.
MPSA18 is probably the most used one, excellent for LTP.
Higher current examples are excellent for use as VBE multipliers.
I am interested in the possibility of using a super-beta driven by a tube because small signal tubes don't like to drive into the relatively low impedance of a regular BJT. So I'm wondering how do they compare with FETs (also tube friendly to drive) in terms of linearity, capacitance and reliability ?
I wouldn't call the MPSA18 a super-beta, with Hfe > 500, not that much better than the old BC549C.
With Ft of about 100MHz, gain is going to start falling at around 100KHz
MPSA18 MOT: hfe 500-1500 (DC, Ic = 10mA)
BC546C-BC550C NXP hfe 420-800 (DC, Ic = 2mA)
go also to
But to a closer view to the exactly curvatures you are right with your view in your previous post because it is not possible, to compare the mentioned current gain values without the conditions of measurement. Sometimes the collector currents are different, sometimes the Uce voltage. Additional this is still a frequency dependend value (compare DC-HFe and AC-HFe).
Unfortunately all the other high Hfe types from Motorola's MPS-series are darlingtons:
BTW - The MPSA18 is sourced from Process 07 (according an old Fairchild Databook)
other types from this process are follow:
more high current gain types:
2N5963 Fairchild (hfe 1200-3000, no genuine datasheet and no successor in S. M. T. resp. SOT23 outline)
2N5962/MMBT5962 Fairchild (hfe 600-2000)
MPSA18 (Onsemi, hfe 500-1500)
2N5088-2N5089 Onsemi hfe 450-1800
MMBT6428LT1G + MMBT6429LT1G (Onsemi hfe 500-1250)
2N5828A General Electric, Semiconductor Data Book 1971 hfe 200-800)
2N5828 datasheet and application note, data sheet, circuit, pdf, cross reference, pinout | Datasheet Archive
2N5526 TI (no datssheet)
2N5249 (GES = General Electric Semiconductor) hfe 40-800
2N5249 pdf, 2N5249 description, 2N5249 datasheets, 2N5249 view ::: ALLDATASHEET :::
2N5223 (Fairchild hfe 50-1600)
2N5223 pdf, 2N5223 description, 2N5223 datasheets, 2N5223 view ::: ALLDATASHEET :::
MMBT5223 (hfe 50-800), MMBT2484 (hfe 250-800)
MMBT5223 datasheet and application note, data sheet, circuit, pdf, cross reference, pinout | Datasheet Archive
2SC2545, 2SC2546 Hitachi (hfe 250-1200)
ZXTN07045EFF (Zetex hfe 500-1500)
ZXTN07012EFF (Zetex hfe 500-1500)
ZXTN07012EFFTA pdf, ZXTN07012EFFTA description, ZXTN07012EFFTA datasheets, ZXTN07012EFFTA view ::: ALLDATASHEET :::
ZXTP25012EFH (Zetex hfe 500-1500)
ZXTC2061E6 (Zetex Dual Transistor, hfe 500-1500)
MBT6429DW1T1G (Onsemi Dual hfe 500-1250)
UMZ1NT1G (Onsemi Complementary Dual Transistor hfe 200-400)
More high gain examples from Japan:
2SD2159 (Rohm hfe 390-2700)
2SB1461/2SB1425 (Rohm hfe 270-1200)
2SD2172 (Rohm hfe 560-2700)
No datasheet online
2SD2356-2SD2226K (Rohm hfe 560-2700)
2SD2227S (Rohm hfe 1200-2700)
Datasheet from March 1997:
2SD2171S pdf, 2SD2171S description, 2SD2171S datasheets, 2SD2171S view ::: ALLDATASHEET :::
2SC3615/2SC3616/2SC3622/2SC3622A (NEC hfe 800-3200)
2SC3615 pdf, 2SC3615 description, 2SC3615 datasheets, 2SC3615 view ::: ALLDATASHEET :::
2SC3616 pdf, 2SC3616 description, 2SC3616 datasheets, 2SC3616 view ::: ALLDATASHEET :::
2SA1409, 2SA1410 (NEC no data)
Any improvement in some caracteristics will inevitably reduce the abilities
of the device in some other areas.
The Hitachi/Renesas 2SA872/2SC1775 complementary pair
has respectable gain of up to 1200 , certainly less than the super beta
devices debated above , but more certainly they have high VCE and FT ,
very low noise and are somewhat a very wise compromise in matter of global caracteristics.
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