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Need 2SC4883 and 2SA1930 or equivalent

Discussion in 'DIY' started by Alan0354, Jul 13, 2017.

  1. Alan0354

    Alan0354 Super Member

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    I have problem finding these two parts, I checked Digikey, Mouser, Newark and Allied, no luck, Mouser won't have the 2SA1930 available until 9/25/17, I ordered the 2SA1930 already. I just cannot find 2SC4883. I looked and there's no equivalent. These are 200MHz 150V or 180V transistors in TO220

    I have two members here want to build my amp, I have enough for myself, but they need these. Any suggestion of a place to buy? Or equivalent?

    Thanks
     
  2. FootFungus

    FootFungus Well-Known Member

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    Quest Components.
     
  3. Alan0354

    Alan0354 Super Member

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    I don't need to be exactly TO220, but I need to mount onto the heatsink as I have another NPN transistor driver mount on the same heatsink to cancel out the temp coef. I can take a TO126!!!

    Maybe that's an idea :thumbsup:
     
  4. jheu02

    jheu02 AK Subscriber Subscriber

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    Deleted my post after looking up the Power rating. 500mW won't cut it for what you're looking for.
     
    Alan0354 likes this.
  5. Alan0354

    Alan0354 Super Member

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    No John, you just trigger idea, I don't need TO-220, I can use TO-126. I need to mount onto the heatsink for temp compensation of Vbe with the opposite transistor. But I only need to dissipate like1W ( 10mA 50V=0.5W or max 1W). My mind was stuck with TO-220 that I have been using. But there is nothing stopping me using a TO-126. I am using KSC3503 and KSA1381 already. They are over 200V, 150MHz and like less than 3pF capacitance. I already have plenty of them, dirt cheap. I am going to try them.

    Your post might be the very post I need!!!!......If this work out. I still need to check how well the thermal compensation is.
     
  6. sregor

    sregor AK Subscriber Subscriber

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    although it looks like you solved your problem, mouser has 2sc5171 which is compliment of 2sa1930.
    Edit check shows none in stock...
     
  7. Alan0354

    Alan0354 Super Member

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    Thanks Steve,

    I did not solve the problem. This is old age you younger people have to look forward to. I gone through this 3 years ago when I choose the transistors, because it's a folded 3EF, the Vbe value is very important. I need as low Vbe voltage as possible to make the bias spreader work. That's the reason I chose a big TO-220 as the first stage pre-driver that only need to drive 10mA. But this still give me a route to take a look at what TO-126 on the market that has low Vbe

    Both Digikey and Mouser don't carry 2SC5171 in stock as it's obsolete.

    There are some TO-126 that are interesting KSA1220, KSA1142 and KSC2690 that are over 150MHz and over 1A current. higher current usually implies lower Vbe. Just have to buy some and try.

    But at the same time, I still want to look at 2SC4883 and 2SA1930, they are proven in my boards already.
     
    Last edited: Jul 13, 2017
  8. Alan0354

    Alan0354 Super Member

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    I checked Mouser and the lead time goes down to 4Weeks on the Toshiba 2SA1930. I immediate ordered 100 of them. I am good on the 2SA1930 for life already!!!! I can even afford to spare a few.

    I have a feeling these two are very popular, they had tons of them not too long ago selling everywhere. Toshiba was the sole source of these, Toshiba decided not to make them anymore, then Sanken must have bought the license and start manufacturing them. This period of time is where Toshiba ones ran out and Sanken has not pick up full steam yet. That causes the shortage. Just a few months ago, Sanken was never in the picture when I did the search. It is news to me that Sanken is making 2SA1930 a few days ago. Believe me, I check on stuffs very often.

    Ha ha, last year I was actually considered using this pair as output transistors. Using like 25 pairs to get the power up!!! Then I can take advantage of the high fT for higher bandwidth, better stability and lower distortion. I decided against this as it's too much work to drill that many holes on the heatsink and too much stuffs on the pcb.
     
  9. sregor

    sregor AK Subscriber Subscriber

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  10. FootFungus

    FootFungus Well-Known Member

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    Digikey is showing 2SC5171 as a last time buy until 12/31/2017. Mouser shows you can order them.

    The SOA on the 2SC5171/2SA1930 is pretty poor for a 2A part. Check the Sanken datasheets or even the 1A 2SC4793/2SA1837.
     

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