I need to place a ~5V limit on the output of a current sensor which could potentially spike to 8.3V for a short period of time (~18msec) (manufacturer part number ACS712ELCTR-05B-T). As far as i understand, i just connect the cathode to the positive voltage and the anode to ground... I need help selecting the zener diode, i was looking at the following "1N5337BG" (characteristics in attached image zenerdata). It says the Zener impedance Z_ZT @ reverse current I_ZT is 2.Ohms. Is this the correct reasoning?>>> if there was a 8.3V voltage spike, and the current was diverted through the zener it will see an impedance of 2.Ohms (or will it see a lot less than this?)... , so the zener will need to dissipate P=V^2/R = (8.3^2)/2 = 34.4Watts? It says the maximum steady state power dissipation is 5W and the surge current rating is 15.3A (current would be 8.3/2 = 4.15A) The main thing i am worried about is what impedance the current will see at voltages greater than the zener voltage??