On-Die I/O Driver VOH VOL Parametric Test Circuitry

The patent extracts the testing function from external testing devices and relocates it to on-die test circuitry. The test circuitry, comparator circuitry, and test controller are integrated directly on the die, eliminating the need for external ATE equipment. This extraction resolves the contradiction by removing the time-consuming aspects of external testing (multiple testers, frequent cleaning) while preserving measurement accuracy through on-die voltage comparison against reference levels.

The patent introduces an intermediary test circuitry as a mediator between the I/O driver circuits and the measurement process. The test circuitry includes current sources/sinks that simulate load conditions, comparators that measure voltage levels, and reference voltage generators that provide comparison standards. This intermediary system enables accurate VOH/VOL measurement without requiring external testing equipment, thus reducing test time while maintaining measurement precision.

The patent merges multiple testing functions into a single integrated on-die test system. The test circuitry, comparator circuitry, reference voltage generation, and control logic are combined on the same die, replacing multiple external testers and their associated infrastructure. This merging reduces device complexity and eliminates the need for probe cleaning systems while maintaining comprehensive VOH and VOL parameter testing capability.

The patent implements self-service testing where the device under test performs its own VOH and VOL parameter measurement. The on-die test circuitry is activated during manufacturing or field operation to automatically measure and report voltage levels without external intervention. This self-service approach simplifies the overall testing system by eliminating complex external testing infrastructure while ensuring reliable parameter verification.