Selecting an appropriate ESD protection for discrete RF power LDMOSTs

For ESD protections of RF Power MOSTs, Vt1 lowering by the RF signal – due to the dV/dt effect – can seriously degrade the RF performance. The use of a cascoded protection solves this problem. A new failure mechanism, related to the discharge of on-chip RF matching capacitors is presented. Adding a current limiting resistor in the protection solves this issue. Combining these solutions yields an appropriate protection for discrete RF power LDMOSTs.