ESD/EOS protection circuits for integrated circuits

摘要

An ESD/EOS protection circuit 10. Trigger nMOS transistor M1 has a drain 20 connected to a voltage pad 22, a gate 24 connected to ground 26 and a source 28 connected to ground 26 through source resistor Re. Switch control nMOS transistor M2 has a drain 30, a gate 34 connected to source 28 of transistor M1, and a source 38 connected to ground 26. Current controlled switch (CCS) 40 is connected to voltage pad 22, ground 26 and drain 30 of transistor M2. CCS 40 is a bipolar pnp-based current controlled switch.