Did not find any pre-made adapters. Took your suggestion and designed my own. The IC is LT3958 and it is a power converter IC that can be used as Boost, Flyback, and SEPIC. I am using it in SEPIC mode to get +15V,-15V, and +5V from a 72V battery packDid you find anything? What IC is this for?
Left it that way because it will be easier to orient and solder the IC onto the board. I don't have any hot air guns or Reflow machines and need to do them by hand for the prototypes at least. So having those pins separate will help with alignment.Looks good, but I suggest you extend pads 37 & 38 as per datasheet to minimise track inductances. I'd make it a smaller DIP and consolidate pins eg 1,2,4,23, 36,35,34 are all NC and connected to SGND so don't need to be brought out to individual DIP-pins, similarly for SW (38), 8, 9, 10, 20, 21 and the GND pins 12 - 17... , but may need a couple of pins depending on current to/from external components...
Looking at the SEPIC circuit you actually only need to bring out nominally 8 pins from the carrier, Vin (27), SGND, RT(33) , SS (32), VC (30), FBX (31), GND, SW - I'd put the Vcc bypass capacitor on the carrier from pin 28 to SGND and extend SGND and SW on the back of the carrier to provide additional heatsinking
View attachment 241979
You can make one, or you can buy one if that's simply easier- QFN-36 to DIP (< $11(USD)):Hello everyone,
Does anyone have an idea of where I can buy a 36 pins QFN-DIP adapter with 2 exposed bottom pads? The pinout of the IC is attached below. Closest I could find was a 38 PIN QFN-DIP adapter and that is not working.
View attachment 241827View attachment 241827
Nice try, but wrong size (9x9 not 5x6), wrong pin count/EP count (36/0 v 36/2), wrong pitch (0.8mm v 0.5mm)You can make one, or you can buy one if that's simply easier- QFN-36 to DIP (< $11(USD)):
http://www.proto-advantage.com/store/product_info.php?products_id=3100155
This is better than my design. Thank you for your helpOK, but I think you'll have problems with those long thin tracks...
You can still retian the individual lands, but join them up to each other, e.g.
View attachment 242005
You're welcome. It's not perfect, I still don't like the long runs. Try turning the QFN 45 or 90degrees anticlockwise so the individual pins end up on both sides at top and SW and GND end up on opposite sides at bottom..This is better than my design. Thank you for your help
Yeah. Will do something like this (pic attached below). The screenshot is from my complete design of the final product. Wanted to test it on a breadboard before sending it for PCB manufacturing and ran into this troubleYou're welcome. It's not perfect, I still don't like the long runs. Try turning the QFN 45 or 90degrees anticlockwise so the individual pins end up on both sides at top and SW and GND end up on opposite sides at bottom..
I want to test the chosen values of my passive components. Including them in the PCB design will defeat that purpose.Hmm, why not just make up a small test pcb with just the buck converter on it to verify the layout? You could make a board with a few candidate layouts so you can compare and contrast them. That's what I would do rather than mess with a dip carrier which may introduce other side effects...
What was the problem you were encountering?
And you can't swap parts on a PCB? Breadboarding an SMPS rarely gets the results you expect, too many stray inductances/capacitances and lack of ground planes - modern SMPS chips are quite finicky in this respect. Also lead lengths of through-hole passives on a bb don't translate well to SMD parts on a PCB.I want to test the chosen values of my passive components. Including them in the PCB design will defeat that purpose.
Well, why not go look at their stock. They have more than anybody else I know. Will this one work?Nice try, but wrong size (9x9 not 5x6), wrong pin count/EP count (36/0 v 36/2), wrong pitch (0.8mm v 0.5mm)
Interesting stuff...schmartboard