LT1013 square wave input sawtooth output?

[raviolidon]

Does anyone know what could be going wrong here? I am using a LM555 timer to acheive a 50% duty cycle and 40kHz output, inputted to an LT1013. I do see this output(LM555) and input(LT1013) (squarewave) but the output of my LT1013 is a sawtooth. I have checked the circuit over and over and it should be fine but maybe I am missing something?? I am using +15VDC, R1=1k, R2=10k, C=1500pF, LT1013 is just used as a buffer with pin 2 tied to pin 1.

[pebe]

Your 40kHz square wave signal has an 'on' time of 12.5µs, but the LT1013 has a slew rate of only 0.4V/µs so the output can only rise and fall relatively slowly - hence the sawtooth (triangular?) wave.

The 555 can give an output of 200mA, so do you really need a buffer?