Gate oxide voltage limited devices for digital circuits

摘要

An oxide protection circuit prevents failure of the MOS transistors in a digital device. A voltage difference at a gate oxide of a digital device does not exceed a breakdown voltage magnitude. The gate oxide protection circuit includes a plurality of transistors which turn OFF or ON when a node reaches a predetermined voltage of Vrefp+Vt or Vrefn-Vt, where Vrefp and Vrefn are reference applied at a gate of a PMOS or an NMOS transistor, and Vt equals a threshold voltage of the MOS transistor.