LM47XX series of chip amps

[JoeBob]

Pretty much all of the LM38XX and LM18XX series of chips have been used by members here on these forums, and the OPA5XX chips have also been extensively toyed with, but I can't find any one who has tried the LM47XX chips.

The LM4700/LM4701 looks to be newer parts and asside from the lower power and slightly lower gain bandwidth they have superior specs such as slew rate and SNR. The LM4766 seems a good way to minimalise the gainclone idea even more, have only one chip.

I wonder why no one has tried them. Maybe I'll give them a go, the LM4701 is in a 9 pin package that might work nicely for smaller amps...

 

[Sandy H.]

I wish I could technically give you some information, but I can't. Maybe you've noticed a previously disregarded chipamp option.

I'll look to see if something good comes from it. Go for it, JoeBob! Even if it isn't a perfect performer, I'm sure someone will enjoy learning from your experiment.

Sandy.

 

[ted]

On coincidence I recently I prototyped a GC using a LM4700TF. The PS rails used were +/- 31 volts unloaded. The resulting THD @ 1 watt/8ohms was [ 100hz=.03%, 1Khz=.03%, 10Khz=.04%, 20Khz=.05% ]. Clipping wattage was 22W.

The 3886TF version was below my measurable limit of .01% from 100Hz to 20Khz.

I have a few LM4752T, which I was going to play around with since it has embedded feedback resistors but the big down-side were the output capacitors and a low maximum PS of (40v).

Good Luck on your experments.

 

[JoeBob]

I'm guessing these parts are biased at lower currents, to conserve power most likely. But since THD isn't everything I'd still like to try some out.