The term “5-NINEs availability” is often used, which corresponds to 99.999% availability (5-NINE is the percentage of time the system is operational--this translates to almost zero down time). This level of availability can only be achieved when the cards are serviced by hot-swapping them in and out without powering down the entire system. One must then be able to repair, upgrade, configure, and sometimes even expand the system on the fly without disturbing the rest of the system.

This article discusses some of the “band aid” solutions that some board-level design engineers currently use and continue to use as their hot-swapping circuits. This is followed by a discussion of a few new-generation innovative hot-swapping solutions. We first do a brief presentation of what the term “hot-swapping” means in terms of voltage transients followed by a short discussion of a few solutions designers have used to protect their systems against the effects of hot-swapping. Then we will present the very recent innovations in this technology area from a few suppliers, which fix all the short-term and long-term effects of hot-swapping.

The article is presented in two parts, as pdf files (no registration required):

• To read Part 1, click here
• To read Part 2, click here