Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
Bandwidth is the range of frequencies where your OTA works well considering the Gain. When you exced this BW the gain decreases.
But Slew rate is the maximum velocity of change of signal at the output, usually voltage. It is the capacity of the OTA to follow the input signal amplified. And it is traduced in signal distortion, for example a sinusoidal as a input could result insted of a curves a linear rects, that is distortion.