Microcontroller ESD protection

[rocky79]

I have been looking for a level 4 ESD pin protection on microcontroller pin( pic16f1503).
The micro digital input pin is used to measure pulses between 50us to 200us.

Do you think a circuit like this would work?

R=500 ohms and
C=0.01uF
VESD=V0=15kv ( Level 4)

Vc=V0(1-e^(-t/RC))
Ic=(V0/R)*e^(-t/RC)

the RC filter will take 1.67uS to charge to 5v however the deadly spikes only last 10’s of nano-seconds.
The initial spike current at t=0  is V0/R=(15kv/500)=30 amps.
In order to conduct this damaging current away from the protected component  I added a TVS diode in parallel with the RC.
What do you think about this TVS from littlefuse part# SD05C it has 5v reverse working voltage and clamp at 14.5v 10amps?

Any other suggestions will be appreciated.

[thm_w]

The R needs to be in series with the i/o pin, from what you've drawn thats not correct.
Also I would prefer to use unidirectional TVS. Others may recommend schottky.

http://www.onsemi.com/pub_link/Collateral/AND8424-D.PDF

[rocky79]

The R needs to be in series with the i/o pin, from what you've drawn thats not correct.
Also I would prefer to use unidirectional TVS. Others may recommend schottky.

http://www.onsemi.com/pub_link/Collateral/AND8424-D.PDF

Yes, you're right. I have updated the schematic. Also good point about using a uni-directional TVS. Thank you for the advice!