THX for the models! A little bit higher Cob and lower Vce but maybe a good (and expensive) future replacement for the discontinued 2SC4793/2SA1837.
Due to the lower Vce maybe only usable for SA2015.
Funny: on the Digikey shop there is no information about discontinuation of 2SC4793 - only for the PNP part 2SA1837 with a watermark in the datasheet ...
Have Fun, Toni
Thanks for info/warning. I've ordered 10 pieces
"2SC4793LB-TF3T, 2SA1837LB-TF3T" each from profusion for testing.
BR, Toni
4883/1859 is very good driver especially for Sanken outputs. I use them with 3519/1386, and 6145/2223 with very good results...
Sajti
Sajti
IMHO: a rather high value. I would have expected lower values due to lower fT compared to vertical mosfets but:
- AN1850/LME49830/snaa058a.pdf recommends 22R for 2SK1530, 10R for 2SJ201. (Fig.3, page 3)
- Bob Cordell uses 470R with 2SK1056/2SJ160 (laterals) (DAPA, fig. 11.1/p.216)
- Bob Cordell uses e.g. 100R for verticals 2SK1530, 2SJ201 (DAPA, fig. 11.17, p.242). He also recommends to add a gate/drain zobel (e.g. 100R + 47pF) instead of reducing the speed of the mosfets
http://products.semelab-tt.com/pdf/ApplicationNoteAlfet.pdf
p.11: "Gate Resistor Recommendations": 150R up to 470R.
Maybe a combination of a lower gate resistors and "cordell" gate zobels is the best way?
BR, Toni
According to R.Cordell, it is the opposite.
Due to the Laterals being slightly slower than the Verticals, one needs to use slightly higher values of gate stopper to roll-off the gain at a slightly lower frequency.
I'm too,
I was used in my OPS, with 2SC3423Y/2SA1360Y at pre-driver, 2SC4883A/2SA1859A driver and 2SC2922/2SA1216 output.
Don't worry about a little bit higher Cob, the sound still very good.
They came my reference parts, when i want to built a EF3 OPS.
I was used in my OPS, with 2SC3423Y/2SA1360Y at pre-driver, 2SC4883A/2SA1859A driver and 2SC2922/2SA1216 output.
Don't worry about a little bit higher Cob, the sound still very good.
They came my reference parts, when i want to built a EF3 OPS.
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Those models have been updated with correct Vaf values. The test didn't have very good resolution at high Vaf, so they could be a bit higher than that. In the past I may have sent you previous models with incorrect Vaf.
Sorry - it was not my intention to criticize your bjt models. I meant the difference between the datasheets ... 😉
I will check my "keantoken_bjt_models_standard.lib" and add the new models. Thank you again for your excellent work providing us updated and new spice models! 🙂
Br, Toni
I do encourage you to find out on the bench what are acceptable gate stopper values, because often it's not the FET itself that becomes unstable, but the amplifier driving it. The stoppers can often be lowered quite a bit with good layout and optimized driving circuitry, or with a well-placed RC snubber.
I updated the Cjc of the P Sanken driver. The new models are in my latest model library, attached. There are several improvements:
I updated the Cjc of the P Sanken driver. The new models are in my latest model library, attached. There are several improvements:
Code:
* Version 9:
*
* 2SC4883A/A1859A: Updated Vaf and Cjc with measured values.
* 2SC5171/A1930: Updated with quasi-saturation.
* 2SC3423/A1360: Updated with more reasonable Vaf values, but need measurement.
* BC3x7-40: Updated with measured Vaf values.
* KSC1845E: Updated with measured Vaf values and quasi-saturation.
* KSA992F: Updated with quasi-saturation.
* BC5x0C: Updated with measured Vaf values for different factories.
* MPSA18/MMBT6429 New model with measured Vaf for a Fairchild MPSA18 and Rb according to the OnSemi datasheet.Will do so. The annotation note of semelab presents a formula to pre-calculate such a resistor. The rest is practical work. I own a 150MHz scope so I should be able to check the oscillation sensitivity...
Many thanks - just downloaded!
BTW: the BC560 models still have hFe(BF?) of 900 which I have never seen. Most of my 2k Onsemi BC560CG are in the 600 range and most of my newest 2k Fairchild BC560CTA are in the 450 range.
Thx!
Have fun, Toni
Do the BC560 show too high Hfe in simulation? Sometimes Bf can be higher than the actual beta of the transistor, in order to model an upward slope at low currents better.
Those models are based on Cordell's models, which may have been made for atypical devices.
Those models are based on Cordell's models, which may have been made for atypical devices.
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Hmmm ... OK ... overflow ... sorry ... lack of knowledge here on this side ... thought spice parameter BF = hFe
🙂
Yes
And yes, they don't come out quite as high as Bf would indicate, but still far lower base current is predicted compared to the 550/560C that I use.
Same for me. The Onsemi 550C/560Cs are around Hfe=600, and this is same for the Onsemi 547C/557Cs too.
Sajti
If Vaf is low, Bf might be significantly higher at high Vce. Has anyone tested the Hfe at 40V or so? I'm rethinking the Vaf values, my test circuit may be faulty. I think I will just delete the new BC5x0C models since Cordell's models have always worked for me.
SA2013, SA2014, SA2015 housekeeping circuits
SA2013, SA2014, SA2015 housekeeping circuits
I've been asked several times mostly via PM to provide more information about the housekeeping circuits which I've developed and used in most of my current amplifier projects. If there's enough positive response here, I will think about providing gerbers and maybe firmware for programming the pic16f690 and the newer replacement pic16f1829...
Have fun, Toni
SA2013, SA2014, SA2015 housekeeping circuits
I've been asked several times mostly via PM to provide more information about the housekeeping circuits which I've developed and used in most of my current amplifier projects. If there's enough positive response here, I will think about providing gerbers and maybe firmware for programming the pic16f690 and the newer replacement pic16f1829...
Have fun, Toni
Today got some UTC 2SC4793LB and 2SA1837LB.
Some measurements with DCA75pro and my smart tweezer ST5. Maybe a real life test follows.
BR, Toni
