Trying to convert old TH amp designs to SMT as an exercise, I am looking for surface mount equivalents of 2SA992/2SC1845 and 2SA1381/2SC3503.
The first pair could be replaced by FJV992/1845 kind of hard to find, any better ideas?
No clue for the second pair. Any suggestions? Thanks.
The first pair could be replaced by FJV992/1845 kind of hard to find, any better ideas?
No clue for the second pair. Any suggestions? Thanks.
I think that converting to SMT the 2SA1381/2SC3503 is simply not advisable.
You would be better with those smart TO126 transistors which can benefit being placed on a heatsink.
For the first pair you can have a look to ONSEMI MMBT5401L/MMBT5550L
You would be better with those smart TO126 transistors which can benefit being placed on a heatsink.
For the first pair you can have a look to ONSEMI MMBT5401L/MMBT5550L
The SOT223 types are thermally quite good. If you create some space around them, you can glue a heatsink on on top.
Put a dab of RTV either side of the device and then a small amount of heatsink compound on top then push the heatsink down and let the RTV cure.
Of course, make sure you put plenty of copper down. The data sheet thermal performance specs will provide guidance.
It will be good to see how your project goes.
Put a dab of RTV either side of the device and then a small amount of heatsink compound on top then push the heatsink down and let the RTV cure.
Of course, make sure you put plenty of copper down. The data sheet thermal performance specs will provide guidance.
It will be good to see how your project goes.
I was looking at doing the same and came up with the same parts for consideration.
I also found a few more as well, for duals FMBM5551, FMBM5401
Of course Diodes DMMT5401 and Onsemi FMBM5401 are not the same pinouts. DMMT5401 is 300mW and FMBM5401 is 700mW
I have seen some, solder copper flags or strips to the large collector pad to make a vertical heatsink for the SOT-223.
Standardizing on the SOT-23 or SC-59 allows for many possibilities and suppliers
I also found a few more as well, for duals FMBM5551, FMBM5401
Of course Diodes DMMT5401 and Onsemi FMBM5401 are not the same pinouts. DMMT5401 is 300mW and FMBM5401 is 700mW
I have seen some, solder copper flags or strips to the large collector pad to make a vertical heatsink for the SOT-223.
Standardizing on the SOT-23 or SC-59 allows for many possibilities and suppliers
I have used DZT5401 with great success as a preamp or headphone amp output stage. I would imagine the DZT5551 would also work just as well. They are good for 600mA and can dissipate 1W. Great drivers. They sound very nice. Make sure you provide enough PCB thermal pad for a heatsink.
I feel these can be used where projects call for obsolete Toshiba 2SA1837 and 2SC4795.
I feel these can be used where projects call for obsolete Toshiba 2SA1837 and 2SC4795.
Thanks guys, your suggestions will get me started.
Here's some data from TI on how to properly dimension PCB copper heathsinks for optimal SOT-223 dissipation.
Here's some data from TI on how to properly dimension PCB copper heathsinks for optimal SOT-223 dissipation.