I/sub DD/ pulse response testing on analog and digital CMOS circuits

Abstract

lhis paper presents a new method for detecting defect and fabrication variations in both digital and analog CMOS circuits by simultaneously puking the power supply raik and analyzing the temporal andlor the spectral characteristics of the resulting transient rail currents. lhe method presented has a distinct advantage over other forms of iDD testing because it requires a single test vector to excite and expose the presence of a defect or irregular fabrication process condition. lhis paper presents data fhom simulations and defective IC's supporting this technique.

Defect classes-an overdue paradigm for CMOS IC testing

“…Nontarget tests, such as at-speed Boolean methods, are the only tests available. Other tests, such as the transient power supply current test, i,l,x, require further research to describe their capabilities [74,75].…”

A comparative analysis of input stimuli for testing mixed-signal LSIs based on current testing

“…This method provides a high fault coverage at a lower testing cost. Similar techniques have been proposed for mixedsignal circuits, [7], [8]. These methods involve monitoring the power supply current (IDD) waveform of the circuit under test (CUT) and comparing it with the waveform produced by the fault-free circuit.…”

Using Fourier analyses to enhance IC testability

“…It appeared [6] that our method could detect faults that are undetected by IDDQ testing, such as stuck-open faults [3]. Moreover, IDDQ testing is limited to technologies with zero or very small quiescent currents [4]. As it is explained later, the applicability of our method should not be limited only to these technologies.…”

“…Our method is different since only a small part (DC and first harmonic) of the frequency spectrum is estimated using a simple FFT on a few current samples. Beasley et al [4] presented a method which pulses VDD and GND signals while the inputs are siet t o a fixed bias voltage. In their paper, they showed that the supply current frequency spectrum of a defective circuit varied a defect-free circuit without proposing any method t o used this information.…”

“…In their paper, they showed that the supply current frequency spectrum of a defective circuit varied a defect-free circuit without proposing any method t o used this information. However, the fact that the entire circuit is stimulated makes single defects less obvious [4]. Moreover it requires simulations of the entire circuit in order to get reference results, which becomes untractable for large VLSI IC's.…”