I need one clarification regarding ESD,EFT and SUrge protectors. Different manufacturers have architectures of diodes+Zenar diode combinations for different protection levels for different interfaces.
I am attaching a figure which shows 2 architectures of ESD suppressors. What factor determines how manufacturer connects these diodes and zenar's in a specific way. in the figure attached 2 components 1. 2 zenar's with anodes connected to each other and cathode terminals are exposed outside - CDSOT23-SM712 for RS485 Protection 2. same 2 Zenar diodes with 2 cathodes connected internally and anodes exposed outside - PGB1 for USB protection.
for analysis if any ESD event occurs , if voltage is > Forward voltage of one zenar+ reverse voltage of zenar, then device will protect.
I am really curios to know why these architecures done in this way. Please correct me if i am wrong. my intention is in both cases breakdown will happen in same way, how we can we say which architecure is good for RS485 or USB.