Delta I Measurement Technique
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27
A method is described for measuring the full AC current waveform of packaged VLSI chips. The AC current waveform is required to determine the delta I which allows calculating the effective inductance of the chips plus package (module and card). The AC current is generated either by an off-chip driver or by internal latch switching. It is well-known that the voltage drop across the inductances of chip and package limits the module performance. Therefore, it is important to measure the AC current carefully and accurately and to obtain data on the behavior of future packages by circuit simulation. Fig. 1 shows how this measuring method is carried out.