Brief:
I want to implement the ESD & Transients protection to my circuit using current limiting resistor is typically 100 ohms to 1K ohms which forms a pole with the diode capacitance.I meant to say a transient clipping circuit using a series resistor and rail-to-rail diodes

Question:
Please let me know how to calculate the slew rate for this circuit ?

 

Hello,

Does this help?
http://en.wikipedia.org/wiki/Slew_rate

Bertus

 

You can keep your slew rate pretty high by using small diodes. 1N4148/1N914 are limited to around 100mA, but are extremely fast (~4nS switch time max), and have a low capacitance (<4pF @1MHz.) Compute your RC time for resistance vs 2 junctions.

1N4148/1N914 diodes do have a somewhat high Vf at low currents. You might look at Schottky diodes, like BAT54's or the like. They're fast and have a very low Vf.