3W IC amp - TDA7267A

[AC_FX]

Here's another chip amp.  The chip is obsolete, but easy to find.  Velleman has a PCB kit for this circuit, but it's certainly simple enough to do on stripboard.  I built this layout today, it's verified.

[Heath]

What difference, if any, does the voltage swing between 6v and 15v make?

[AC_FX]

Heath, I've run this at 9V, 15V, and 20V, and the difference is about what you'd expect - it works better, i.e. more clean headroom, when supplying it with more voltage.  

[Heath]

Any idea why the kit instructions say explicitly to NOT use an IC socket?  Sounds odd to me.

[Frank_NH]

Here's the datasheet:

TDA7276A Data Sheet

Looks like you need to secure the chip to a heat sink to cool it.  Maybe someone makes an appropriate mount.  I certainly wouldn't use a standard plastic IC socket.

[Heath]

D'oh!  That went right over my head.  Yes, yes, melting sockets is bad.

Thank you!

[AC_FX]

The kit instructs you not to socket it because the PCB has a lot of uninterrupted copper serving as both a ground bus and a heat sink.  Socketing the IC will leave the ground pins with less of a physical connection to all that, making it a less effective heat sink.

When I want to add a heat sink to an IC like this one, I use a clip-on one with fins, Mouser part number 532-580200B00.