BC337 hfe distribution
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From: Jim Thompson on 10 Apr 2010 10:49 On Fri, 9 Apr 2010 16:32:12 -0700, "Joel Koltner" <zapwireDASHgroups(a)yahoo.com> wrote: >Hi Jim, > >"Jim Thompson" <To-Email-Use-The-Envelope-Icon(a)On-My-Web-Site.com> wrote in >message news:cjcvr5prd90rvnu494d5fqu92nh3lgos1n(a)4ax.com... >> PSpice supports LEVEL=1, 2, 3, 4, 5 (EKVv2.6), 6 (BSIM3v2.0), and 7 >> (BSIM3v3.2) > >Has that ever been a problem for you, yet -- that PSpice hasn't added any of >the newer models? PSpice just numbers them differently, IIRC, LEVEL=7 in PSpice is HSpice LEVEL=58 > Or do all the foundaries still provide older models even >once the new ones are available? Rarely > >> Other simulators use different numbering conventions... HSpice lists >> them up to (IIRC) ~ LEVEL=58, never dropping any model numbers that >> were flops :-) > >It looks good to pointy-haired managers when they can say, "We have 58 >transistor models, our competitors only have (the) 8 (that are actually used >anymore)!" > >---Joel Yep. Unfortunately these models are often the product of PhD's :-( So their notation can dwell close to total obfuscation. When I recently got on XFAB's case in regards some massive simplifications that could be done, they got all huffy and defensive, claiming "ease of updates throughout all simulator styles" :-) ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | The only thing bipartisan in this country is hypocrisy
From: legg on 10 Apr 2010 12:05 On Fri, 9 Apr 2010 22:27:10 +0300, "E" <invalid(a)invalid.invalid> wrote: >Just measured hfe from some BC337-40 at about 5 mA collector current. >Unfortunately nothing very interesting there > >Results: >Sample size: 960 pcs >minimum hfe: 388 >maximum hfe 513 >(datasheet limits are 250 and 630) >avarage: 452 >avarage deviation: 27 >median: 463 >mode: 477 >Distribution is a bit strange looking with two spikes >Histogram here: http://koti.mbnet.fi/hsahko/hfe/ > >-ek > BC337-40 is a binned-by-hfe part number, so you can't expext a 'natural' hfe distribution curve. For such a natural distribution, you'd need a part number not subject to selectuive processing, 'probably' made by a firm that does not offer that service for any of it's produce. RL RL
From: E on 10 Apr 2010 14:15 "legg" <legg(a)nospam.magma.ca> kirjoitti viestiss�:u381s55up8gpbbc8t30ka4g4spc0lkcv5v(a)4ax.com... >>-ek >> > BC337-40 is a binned-by-hfe part number, so you can't expext a > 'natural' hfe distribution curve. > Yes, it is hfe binned part. Unfortunately I don't have many non-hfe binned transistors, but found some MPSA42 high voltage bipolars. hfe distribution is actually pretty similar in those than in bc337. Min-max:118-142, relative avarage deviation: 2.6% Maybe I need to buy some more of them to get some idea about batch-to-batch variation > For such a natural distribution, you'd need a part number not subject > to selectuive processing, 'probably' made by a firm that does not > offer that service for any of it's produce. >
From: Robert Latest on 10 Apr 2010 15:14 Jim Thompson wrote: >>> >>> Possibly, alltought they were all from same bag. >>> Or maybe just from different wafers? >>> How many BC337 fit one wafer? Probably quite many... >>> >> >>Perhaps they take all the middle ones for a tighter-spec version? > > Roughly 80K _untested_ die (if wafer is 8"). I can only speak for NXP, but it's more like 200k on a 6" wafer (I can look up the actual number). > The wafer is probably > auto-probed and binned into various device numbers. Not quite. They auto-bin whole wafers into different selection groups of the same type. Meaning that entire wafers end up in one group. > Discrete device production is so automated... it's fascinating to > watch the automated handling equipment :-) Absolutely. More than 10pcs/sec eutectic die bonding and wire bonding, and a whole assembly line still many hours for a single BAV99 wafer. robert
From: Robert Latest on 10 Apr 2010 15:15
E wrote: > They have still not managed to get their processes so much under control Yes they have. > that they can make what is needed instead of what happens to come out? They do. Maybe it hasn't been always that way, but nowadays when a batch starts into the line as BC547 it'll come out as 547. robert |