Re: U1 fried

Jerry Gaffke

Ah, the TDA82822D part in the SOIC8 package is a good find.
Feeling much better now!

Digikey has it for a bit over a dollar (Mouser says a minimum buy of 2000).
Maybe hfsignals will move to the more easily gotten SMD part if they ever roll the board.
Though I'm pretty sure I could solder the SMD into place with just some short wires,
not bothering with the adapter board.

> The chip is rated to work with a 4Ω load so a 4Ω resistor should do. I doubt the chip would blow so fast that FB fuse wouldn’t protect it.

Yes, I think a 4 ohm resistor would probably do, I was getting rather cautious when I saw how hard the M part was to obtain.
I'm suspicious that with a 12v supply it is close to the edge, they seem to blow with little provocation.
Most of the datasheet seems to assume a max of 9v.
The fact that it works down to 1.8v reinforces this notion.

The fuse might protect it, depends on the failure mode.
The fuse costs about as much as the TDA2822D.


On Wed, Feb 28, 2018 at 04:02 pm, Clark Martin wrote:
The TDA2822D in effect replaces the “M” version.  It appears the same except it’s an SMD part.  You can get SMD to through hole adapter boards that would let you use one with the µBitX.  It would likely be cheaper than buying the “M” version.

Join to automatically receive all group messages.