On-chip iDD pulse response method using a high-speed dynamic current sensor

This paper presents design considerations for a high-speed dynamic current sensor for iDD analysis. This testing scheme, known as the iDD pulse response method is a built-in scheme for analog, digital and mixed-signal circuitry compatible with the IEEE 1149.4 mixed-signal test bus standard. A high-speed dynamic current sensor is required for this method-and is described in this paper. Simulation results are provided for the current sensor used to observe the iDD supply current of analog and digital devices. Simulation results include iDD waveforms of defect-free circuits, for circuits with parametric/global faults, and circuits with catastrophic faults. This testing technique serves as an early screening method for defect-free circuits and will potentially allow a fault-free IC to enter the market in significantly less time.