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I'm trying to replace an existing ESD diode(PESD1CAN) in my application CAN circuitry due to some reasons, I've found an alternative ESD diode(RSB27C2), but compared to the diode that I already have in my circuit, it's not that great clamping negative voltages as depicted in the below picture.THe above graph is for the new diode that I'm considering and the below one is for the already existing diode in my circuit. I'm assuming that the negative scale is not shown but the green curves denote the clamped voltage during a negative ESD pulse and the horizontal axis is the timescale : 50ns per division, so I see that for about 100ns the clamped voltage would be about -75V , whereas my existing diode is better at clamping it to -45V. enter image description here

What I'm interested in knowing is how this would affect the components on the line where the voltage is being clamped, enter image description here In my understanding, the negative clamped voltage would appear at CANL and Gnd, and how this extra negative voltage for a very short time(100ns) would impact C418, R413, R414, C410 and the common mode choke L400

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  • \$\begingroup\$ You chopped off the timescale on the graph \$\endgroup\$ – Voltage Spike May 21 '19 at 19:00
  • \$\begingroup\$ This seems to be a popular question. Related recent one ... electronics.stackexchange.com/posts/comments/… \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 May 21 '19 at 19:13
  • \$\begingroup\$ @SunnyskyguyEE75 Related question ,but not the same question. \$\endgroup\$ – NIDHI May 21 '19 at 19:24
  • \$\begingroup\$ What does the layout look like? parasitic inductance can drastically reduce the effectiveness of the diodes. \$\endgroup\$ – Voltage Spike May 21 '19 at 19:43
  • \$\begingroup\$ CAN you not compare max. Specs against your results. 75V exceeds input. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 May 21 '19 at 19:49

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