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Maximum switching frequency for MJE13005 ?

Started by Unknown January 12, 2016
Could some electronics guru please help ?
I am trying to find out the maximum switching 
frequency fro the MJE13005 ? Both the Central 
Semiconductor and OnSemi datasheets do not 
provide any clear information -- "high frequency
switching applications" -- but how high ? I 
know that the maximum switching frequency 
forthe 2N3055 is 4.2 MHZ.   Any hints/pointers/
suggestions would be helpful. Thanks in advance.
 
daku
> > > I know that the maximum switching frequency > for the 2N3055 is 4.2 MHZ.
** No you don't.
> Any hints/pointers/ > suggestions would be helpful.
** Try asking a question that has an actual meaning some day. Amaze everyone. .... Phil
On Mon, 11 Jan 2016 20:44:34 -0800 (PST), dakupoto@gmail.com wrote:

>Could some electronics guru please help ? >I am trying to find out the maximum switching >frequency fro the MJE13005 ? Both the Central >Semiconductor and OnSemi datasheets do not >provide any clear information -- "high frequency >switching applications" -- but how high ?
There's no hard value. But why use that old, slow, low gain klunker? Why not a mosfet? I
>know that the maximum switching frequency >forthe 2N3055 is 4.2 MHZ.
Where did that number come from? A 3055 is pretty slow, and can't do anything useful at 4 MHz. Ft is only 2.5. -- John Larkin Highland Technology, Inc lunatic fringe electronics
wrote in message 
news:6bd72a73-c673-42bd-a1b3-b62d5707b47e@googlegroups.com...
> Could some electronics guru please help ? > I am trying to find out the maximum switching > frequency fro the MJE13005 ? Both the Central > Semiconductor and OnSemi datasheets do not > provide any clear information -- "high frequency > switching applications" -- but how high ? I > know that the maximum switching frequency > forthe 2N3055 is 4.2 MHZ. Any hints/pointers/ > suggestions would be helpful. Thanks in advance. >
Did you see the switching time specs? t_d t_r t_stg t_f Note the collector (load) current and base current (I_B1 = on, I_B2 = discharge/turnoff) figures. The larger the ratio I_B2 / Ic, the faster t_stg is. 2N3055 might have a smigeon of power gain at 4.2MHz, given appropriate source and load impedances. There's no way in hell you've seen an authentic one* _switching_ that fast... *I qualify this statement, on the off chance that some idiotic manufacturer put a screaming fast audio transistor inside one, e.g. 2SC3519 http://www.semicon.sanken-ele.co.jp/sk_content/2sc3519_ds_en.pdf which has an fT up to 55MHz at the right current! In general, BJTs aren't useful for switching above maybe fT / 10. I've used MJE1300x series transistors at 200kHz before; switching losses will be too high for them to be useful much above that. There is no hard frequency cutoff, only a derating due to RBSOA and switching losses. Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com
On Tue, 12 Jan 2016 03:06:40 -0600, the renowned "Tim Williams"
<tiwill@seventransistorlabs.com> wrote:

>wrote in message >news:6bd72a73-c673-42bd-a1b3-b62d5707b47e@googlegroups.com... >> Could some electronics guru please help ? >> I am trying to find out the maximum switching >> frequency fro the MJE13005 ? Both the Central >> Semiconductor and OnSemi datasheets do not >> provide any clear information -- "high frequency >> switching applications" -- but how high ? I >> know that the maximum switching frequency >> forthe 2N3055 is 4.2 MHZ. Any hints/pointers/ >> suggestions would be helpful. Thanks in advance. >> > >Did you see the switching time specs? >t_d >t_r >t_stg >t_f > >Note the collector (load) current and base current (I_B1 = on, I_B2 = >discharge/turnoff) figures. The larger the ratio I_B2 / Ic, the faster >t_stg is. > >2N3055 might have a smigeon of power gain at 4.2MHz, given appropriate >source and load impedances. There's no way in hell you've seen an >authentic one* _switching_ that fast...
Small signal current gain cutoff frequency fhfe is 10kHz. (JEDEC registered number).
>*I qualify this statement, on the off chance that some idiotic >manufacturer put a screaming fast audio transistor inside one, e.g. >2SC3519 >http://www.semicon.sanken-ele.co.jp/sk_content/2sc3519_ds_en.pdf >which has an fT up to 55MHz at the right current!
Plausible fear, but that would be a cruel trick- I bet a lot of old circuits would do 'undesirable' things.
>In general, BJTs aren't useful for switching above maybe fT / 10. I've >used MJE1300x series transistors at 200kHz before; switching losses will >be too high for them to be useful much above that. > >There is no hard frequency cutoff, only a derating due to RBSOA and >switching losses. > >Tim
--sp -- Best regards, Spehro Pefhany Amazon link for AoE 3rd Edition: http://tinyurl.com/ntrpwu8 Microchip link for 2015 Masters in Phoenix: http://tinyurl.com/l7g2k48
"Spehro Pefhany"  wrote in message 
news:2vh99bt69lg9m8b9i3kb4p8s5kvkqar4u1@4ax.com...
> Small signal current gain cutoff frequency fhfe is 10kHz. (JEDEC > registered number). > ... > Plausible fear, but that would be a cruel trick- I bet a lot of old > circuits would do 'undesirable' things.
*MINIMUM* registered number! I suspect transistors that bad, haven't been made in a very long time, and can't even be made anymore. This is why I explicitly avoid anachronisms like 2N3055 and 2N/PN2222 -- the specs can exceed the JEDEC listings by an unknown amount. I've tested "2N3055"s in a circuit like this, http://seventransistorlabs.com/Images/LED_Light2.png at lower voltage (12V supply) and higher hFE (3 to 30 turns on the feedback/drive transformer). A 2N3055 from the '70s went slow as molasses (like you'd expect), one from the '90s worked just as well as a (presumed good) MJ15010, with something like 400ns switching edges. They (2N3055s) might very well be a sale path for otherwise-good dice that fail to meet spec on a more expensive transistor type. Or, they make more on quantity by using the same (in-spec) dice in multiple parts. The "good" ones also have low Vce(sat), like any other regular transistor. (As for "bad" ones, I suspect you're more likely to get a 2N2222 die in your 2N3055, say if you order direct from China. Counterfeits are a real thing, but they're usually about shoddy packaging or inferior die size. But that's a whole 'nother can of worms.) No thread is complete without pics -- take a look at this comparison of GP transistors: http://zeptobars.ru/en/read/NXP-BC847B-bjt-npn http://zeptobars.ru/en/read/OnSemi-MMBT2222A-MMBT2222AL1G-npn-bjt-transistor http://zeptobars.ru/en/read/CHANGJIANG-MMBT2222A-npn-bjt-transistor On Semi tends to care more about their transistors, though I forget if they spec their '2222's as if they're a fully in-house part, or if they follow the JEDEC spec and that's that. Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com
On Tuesday, January 12, 2016 at 12:34:28 AM UTC-5, John Larkin wrote:
> On Mon, 11 Jan 2016 20:44:34 -0800 (PST), dakupoto@gmail.com wrote: > > >Could some electronics guru please help ? > >I am trying to find out the maximum switching > >frequency fro the MJE13005 ? Both the Central > >Semiconductor and OnSemi datasheets do not > >provide any clear information -- "high frequency > >switching applications" -- but how high ? > > > There's no hard value. But why use that old, slow, low gain klunker? > Why not a mosfet? > > > I > >know that the maximum switching frequency > >forthe 2N3055 is 4.2 MHZ. > > Where did that number come from? A 3055 is pretty slow, and can't do > anything useful at 4 MHz. Ft is only 2.5. > > > > > > > -- > > John Larkin Highland Technology, Inc > > lunatic fringe electronics
Yes, MOSFETs are definitely an option, but I "klunkers" like 2N3055 have done performed very well for our designs in the recent past.
On Tuesday, January 12, 2016 at 3:53:29 PM UTC-5, Tim Williams wrote:
> "Spehro Pefhany" wrote in message > news:2vh99bt69lg9m8b9i3kb4p8s5kvkqar4u1@4ax.com... > > Small signal current gain cutoff frequency fhfe is 10kHz. (JEDEC > > registered number). > > ... > > Plausible fear, but that would be a cruel trick- I bet a lot of old > > circuits would do 'undesirable' things. > > *MINIMUM* registered number! I suspect transistors that bad, haven't been > made in a very long time, and can't even be made anymore. > > This is why I explicitly avoid anachronisms like 2N3055 and 2N/PN2222 -- > the specs can exceed the JEDEC listings by an unknown amount. > > I've tested "2N3055"s in a circuit like this, > http://seventransistorlabs.com/Images/LED_Light2.png > at lower voltage (12V supply) and higher hFE (3 to 30 turns on the > feedback/drive transformer). A 2N3055 from the '70s went slow as molasses > (like you'd expect), one from the '90s worked just as well as a (presumed > good) MJ15010, with something like 400ns switching edges. > > They (2N3055s) might very well be a sale path for otherwise-good dice that > fail to meet spec on a more expensive transistor type. Or, they make more > on quantity by using the same (in-spec) dice in multiple parts. > > The "good" ones also have low Vce(sat), like any other regular transistor. > > (As for "bad" ones, I suspect you're more likely to get a 2N2222 die in > your 2N3055, say if you order direct from China. Counterfeits are a real > thing, but they're usually about shoddy packaging or inferior die size. > But that's a whole 'nother can of worms.) > > No thread is complete without pics -- take a look at this comparison of GP > transistors: > http://zeptobars.ru/en/read/NXP-BC847B-bjt-npn > http://zeptobars.ru/en/read/OnSemi-MMBT2222A-MMBT2222AL1G-npn-bjt-transistor > http://zeptobars.ru/en/read/CHANGJIANG-MMBT2222A-npn-bjt-transistor > > On Semi tends to care more about their transistors, though I forget if > they spec their '2222's as if they're a fully in-house part, or if they > follow the JEDEC spec and that's that. > > Tim > > -- > Seven Transistor Labs, LLC > Electrical Engineering Consultation and Contract Design > Website: http://seventransistorlabs.com
While it is very true that a Chinese fake devices barely meet the pre-defined device specifications, a number of local manufacturers in several countries provide genuine devices which, as expected, are more expensive.In India for example, two government owned electronics companies nabufacture and sell devices as 2N3055, MJE13005 etc., In these places, if you buy devices in bulk from wholesalers, they will specifically ask if you want the el cheapo ones or higher quality local makers.
On Tuesday, January 12, 2016 at 12:34:28 AM UTC-5, John Larkin wrote:
> On Mon, 11 Jan 2016 20:44:34 -0800 (PST), dakupoto@gmail.com wrote: > > >Could some electronics guru please help ? > >I am trying to find out the maximum switching > >frequency fro the MJE13005 ? Both the Central > >Semiconductor and OnSemi datasheets do not > >provide any clear information -- "high frequency > >switching applications" -- but how high ? > > > There's no hard value. But why use that old, slow, low gain klunker? > Why not a mosfet? > > > I > >know that the maximum switching frequency > >forthe 2N3055 is 4.2 MHZ. > > Where did that number come from? A 3055 is pretty slow, and can't do > anything useful at 4 MHz. Ft is only 2.5. > > > > > > > -- > > John Larkin Highland Technology, Inc > > lunatic fringe electronics
I am sorry for the typo, the maximum switching frequency for the 2N3055 is indeed 2.4 MHz.
daku...@gmail.com wrote:

> > > I am sorry for the typo, the maximum switching frequency for the > 2N3055 is indeed 2.4 MHz. > >
** But only on planet Daku. .... Phil