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