Fail-safe and high voltage tolerant test control circuitry for an integrated circuit (IC)

An electrical system comprising:

• a main board;
• a pad interface configured to provide a conductive interface between the main board and an integrated circuit (IC);
• and
• test control circuitry configured to selectively transmit one or more electrical test signals between the IC and the pad interface based on a first asynchronous electrical supply and a second asynchronous electrical supply, the test control circuitry comprising:
• first switching stage circuitry configured to enable electrical flow through the first switching stage circuitry based on the first asynchronous electrical supply;
• second switching stage circuitry configured to enable electrical flow through the second switching stage circuitry based on the second asynchronous electrical supply;
• and
• intermediate biasing circuitry configured to define an intermediate voltage between the first switching stage circuitry and the second switching stage circuitry,
• wherein the test control circuitry comprises a plurality of transistors each having a maximum voltage rating,
• wherein the second asynchronous electrical supply exhibits a maximum voltage exceeding the maximum voltage rating of all of the plurality of transistors, and
• wherein the test control circuitry further comprises protective circuitry configured to ensure a voltage difference across any two terminals of a particular transistor does not exceed a particular maximum voltage associated with the particular transistor.