2 quick OTA questions

[Christopher List]

Hi List - 

Two quick questions - 

1. The LM13600. What exactly are the "linearizing diodes" for, and is it 
necessary to hook them up?

2. The VC-slew limiter circuit in electronotes has an option for linear 
function. It uses a 2.2K input resistor and a single 2.2K feedback resistor 
from the cap's buffer back to the (-) input on the 3080. Now, if the slew rate 
is really slow, the output could get to be a very different voltage from the 
input. It could go outside the max differential input voltage (5v) and screw up 
the chip - couldn't it?

- Thanks,
Chris