Failure mechanisms and test methods for the SRAM TVC write-assist technique

The transient voltage collapse (TVC) write-assist technique has emerged as a powerful method to enable low-voltage SRAM operation. However, it comes at the expense of higher complexity and vulnerability to errors as the additional peripheral circuitry is exposed to manufacturing defects. In this work, we analyze the TVC technique from a testing point of view. We study the effects of resistive-open defects inside the TVC circuitry and report the presence of a novel SRAM failure mechanism which occurs when the maximum voltage collapse level is not clamped to a fixed value. Finally, an efficient March test solution detecting these defects is presented.