LM4765 / LM4766 Bridged

[Wizardmaxx]

I was wanting build a LM4766 in BTL, but am finding it difficult to find a schematic for this. The diagrams in the datasheets are sparse in detail to say the least. I know there are probably better chips out there, but wanted to make something p2p that would fit onto a single heatsink (i.e. not two LM3886's and the LM4780 is too delicate to work with - the whole LM4766 current capability issue)

I have subsequently found this diagram for a LM4765 and I am assuming that it is pin for pin the same as the LM4766. What would be the simplest mod to this diagram to convert the amp into a BTL.

Is it as simple as changing the inputs on one of the amps (pins 7 & 8) to make it into an inverting amplifier and then using the two outputs to drive a speaker (omitting ground of course).

Also if I was not wanting to use the mute and standby functions do I have to tie the pins down to ground or do I leave them not connected.

All help appreciated.

[IMG][/IMG]

[AndrewT]

Hi,
when you convert one chipamp to inverting, the gain of that chipamp changes and similarly the input impedance changes. This further alters the RC time constants affecting the frequency response.
Far better to generate a dual polarity signal outside the chipamps and keep the chipamps either both inverting or both non-inverting.

There are lots of threads covering this topic.