Effect of Vth shifting in CMOS Transistors under radiation conditions when applying OBT: A case study

Abstract

In this work, we explore the ability of Oscillation-Based Test (OBT) for testing OTA-C filters (Operational Transconductance Amplifier - Capacitor) based circuits under radiation conditions. We adopt an OTA as a case study for testing. The effectiveness of the strategy is qualified by means of fault simulation. It is known that there are several parameters moving when submitting a circuit to radiation, such as carrier's mobility or Threshold Voltage (VTH). This paper presents an exploring experience when trying to test a circuit under environmental radiation conditions. The idea is to observe the oscillation condition for OBT under a radiation-dependent oscillating parameter in order to obtain certain usage limits for the OBT technique, among some other useful conclusions.