HP HP-Bench-Briefs-1977-09-10 free download

File name HP-Bench-Briefs-1977-09-10.pdf

SERVICE INFORMATION FROM HEWLETT-PACKARD SEPTEMBER-OCTOBER 1977 TROUBLESHOOTER3 IN ACTION Flgun 1. TIL S t g d . In Un digital world, Unnktiwvalwofa [email protected] faepect to th.thfeshold voH.g# G9w- mines tho op#.tlon of the cimuk A 8lg- nal abornth. ht@ thre8hokl k I th. n hlghMato nb whether it I 2.8V o 3.0V I r r s unhparsrwtt to th. operation of Un cir- cuit the digital signal and this digital state determines the operation of the IC, not absolute leveis. In Figure 1, if the sig- nal is greater than 2.4 vdts, it Ts a high state and it is unimportant whether the by Jim Bechtold, Editor The traditional equipment can still be level is 2.8 or 3.0volts. Simitarly used, but an important characteristic low state the voltage must be below of dgital IC's is that when they fail, 0.4 volts. It is not important what the ANALOG CIRCUIT TESTING absolute level is as long as it is below they usually fail catastrophically. This means that timing parameters rarely this thr