Several of my recent posts have mentioned the very negative impact of heat on power consumption. This is the first of a two part series of posts on thermal management for low power devices. This information is mostly taken from my "Low Power Design" PDF e-book.
As semiconductor geometries have shrunk, in recent years leakage current has become a significant component of the overall power consumed by ICs. As parts heat up, their leakage current typically increases. It is not uncommon for parts to consume twice as much current at their highest rate temperature than at their lowest. For example, the AD8226 op-amp is rated for -40°C to 125°C. The quiescent current ranges from 325uA at -40°C to 425uA at 25°C to 600uA at 125°C. This is nearly a 100% increase across the temperature span and nearly a 50% increase from “room temperature” to the maximum temperature. You should conduct your current measurements at the temperature your product will normally operate at if not at the temperature extremes too.
Read the complete post at http://cmicrotek.com/wordpress_159256135/.
Download the "Low Power Design" PDF e-book at CMicrotek - Resources