Four tips for accurate power-rail measurements

摘要

In today's electronic designs, power distribution networks (PDNs) have become a key focus for several reasons. For one, the rails now provide lower voltages with tighter tolerances. Rails that were 5 V with 5% tolerance are shrinking to 1.2 V with a 1% tolerance. So designers must now measure signal details just a few millivolts in height. And PDNs may have 10 to 30 power rails. While some are copies, others have unique voltages; rail values can be as low as several hundred millivolts or exceed 10 V.