- Aug 14, 2011
I *think* it's a fundamental flaw in the concept of using a PCB-mounted TO-252 version of the IC. The bottom side of the IC, with the thermal pad, is heatsinked to the PCB itself. You rely on arctic silvering the WRONG side of the IC (the epoxy/plastic top) to the pill/heatsink/host.
I just don't thinke TO-252 ICs have enough:
- Surface area to dissipate the heat to the air
- Volume to absorb the heat in the first place
However, I'm stumped because I feel like if this was the case, we'd be hearing similar complaints about lots of the drivers out there. The Jib 1.8, the Mohgasm 1.8, etc. And we don't - or at least I've never heard anything negative about those drivers.
I've never (until now) wanted to use a TO-252 IC. I've always suffered with the larger packages, as a trade off for knowing they could handle themselves. But obviously people use 252, and *must* be having some luck with it, otherwise I wouldn't see it used so much.
Well, mine may or may not be a moh 1.8A
I just figured that mine was maybe not heatsinked very well or that I got one with an IC that wasn't really performing up to par since I've never heard of anyone having problems with them either. Heck, I figured the diode would have trouble before the driver. Anyway yeah, you could be on to something there about the design of that particular IC package. Maybe I'll try totally covering the driver with thermal epoxy, maybe squish a piece of metal or two on it and see if that helps. heh