Overvoltage protection circuit with overvoltage build-up detection, has second branch activated by output node overvoltage state to change over first branch, to switch off pull-up transistor

摘要

The circuit (30) contains a first protection branch supplied by a high voltage supply rail and containing an output node coupled to a gate of a pull-up transistor (M1) and a second protection branch supplied by the potential associated with the output node, controlled by the high voltage rail and containing an output node coupled to the first protection branch. The second branch is activated if an overvoltage state exists on the output nodes to change over an initial state of the first branch to switch off the pull-up transistor.