Combined oscillation and I_(DDQ) testing of a CMOS amplifier circuit

摘要

A simple test methodology is presented, combining oscillation and quiescent power supply current (I_(DDQ)) testing for detecting bridging and open faults in a CMOS amplifier circuit formed during fabrication. The testing is performed at room temperature (300 K) and also at liquid-nitrogen temperature (77 K) to enhance fault detection. An on-chip built-in current sensor has been integrated to monitor I_(DDQ) of the circuit under test. A simple fault-injection technique has been used for simulating manufacturing defects. The amplifier was designed for operation at ±2.5 V in a standard 1.5 μm n-well CMOS process. It is shown that all faults can be detected through a combined oscillation and I_(DDQ) testing method. Theoretical results obtained from SPICE simulations are in close agreement with the corresponding experimental results on fabricated devices.