SV: Re: Re: [sdiy] THE LM13600/LM13700 STORY

[JH.]

>Also, we should recall that also the LM13600/13700 actually expects current
>sources. It is just that in the relative high voltage drops resistors
>approximate current sources anyway, so it kind a work fairly well anyway.

That's what I meant about the misleading data sheet.

You have 4 resistors: One from the positive supply to the common anode of 
the diodes,
two from the cathodes to GND, and a 4th to feed the input signal.

The 13600 may work nicely with current sources _everywhere_, but as soon as 
you
choose one resistor instead of a current source, you better use resistors at 
the other locations
as well; using current sources _there_, or just higher resistor values, will 
result in increased
nonlinearity, as opposed to what the data sheet suggests.

JH.