During an ESD event, the zener diode incurs breakdown to lower {HEAD ~ the trigger voltage} of the lateral SCR device to within {TAIL ~ a range} of about 5 7 Volts to thereby discharge the ESD current prior to damage of an internal circuit being protected 
During an ESD event , the zener diode incurs breakdown to lower { HEAD ~ the trigger voltage } of the lateral SCR device to within { TAIL ~ a range } of about 5 7 Volts to thereby discharge the ESD current prior to damage of an internal circuit being protected
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH