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Replacement for obsoleted capacitors

beta24

Replacement for obsoleted capacitors

Postby amb » September 18th, 2014, 4:43 am

For C1 and C2, the β24 BOM specifies the Murata RPE series C0G/NP0 radial-lead multilayer ceramic capacitors which are obsolete, and it appears that there is no readily-available equivalent. However, an SMD capacitor in 0805 size can be soldered on the PCB's through-hole pads.

For the Class AB version:
Original: Murata RPE5C2A1R2C2P1B03B 1.2pF +-0.25pF 100V radial lead
Replacement: Murata GQM2195C2A1R2BB01D 1.2pF +-0.1pF 100V SMD 0805

For the Class A version:
Original: Murata RPE5CA2R0C2P1B03B 2.0pF +-0.25pF 100V radial lead
Replacement: Murata GQM2195C2A2R0BB01D 2.0pF +-0.1pF 100V SMD 0805

FYI.
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Re: Replacement for obsoleted capacitors

Postby rx1975 » September 20th, 2014, 4:02 pm

Hi Ti,

These may be a suitable replacement for the class AB version:

BCE Sud (Philips) 2222 680 03128
Data Sheet Link

They don't seem to be available from Mouser/Digikey/etc. but can be found in small quantities on eBay.
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Re: Replacement for obsoleted capacitors

Postby amb » September 21st, 2014, 3:27 am

OK, that's fine, but I don't typically list ebay items in the official BOM.
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Re: Replacement for obsoleted capacitors

Postby cobretti » February 20th, 2015, 12:29 pm

These are picofarads, pico-farads capacitors. Is that really a big deal if I put 1.5pF instead?
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Re: Replacement for obsoleted capacitors

Postby amb » February 20th, 2015, 12:37 pm

You can use 1.5pF, but it will cause the bandwidth to be lowered from 1.4MHz to 1MHz. Still very wideband.
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Re: Replacement for obsoleted capacitors

Postby cobretti » February 20th, 2015, 1:46 pm

Thanks. That's what I thought. Those values are so small that even when soldered slightly above the PCB it will change 0.x picos. 8-)
Another question is about transistors. I would like to use BC546 instead of suggested BC550, and BC556 instead of BC560. Only difference I see is higher Vcbo and Vceo. That shouldn't be a problem. :?: The reason is that I don't like the kinked leads, and Mouser doesn't have BC560 from ONSemiconductors , so I would like to put BC556 instead.
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Re: Replacement for obsoleted capacitors

Postby amb » February 20th, 2015, 1:54 pm

No, the BC546B/556B is not as low in noise as BC550C/560C, and the Hfe is lower. Kinked leads can be easily straightened...
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Re: Replacement for obsoleted capacitors

Postby cobretti » February 20th, 2015, 1:56 pm

You are right. I didn't scroll the datasheet all the way down, I was too quick , uuups :oops:
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Re: Replacement for obsoleted capacitors

Postby goliraja » May 21st, 2018, 10:38 am

Can we use 80-CCR05CX1R2CM (https://www.mouser.com/ProductDetail/80-CCR05CX1R2CM) for C1,C2 (Class AB)?
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Re: Replacement for obsoleted capacitors

Postby amb » May 21st, 2018, 11:39 am

goliraja wrote:Can we use 80-CCR05CX1R2CM (https://www.mouser.com/ProductDetail/80-CCR05CX1R2CM) for C1,C2 (Class AB)?

Yes, looks fine.
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