8.1 Application Information

The LM5069 is a hot swap controller which is used to manage inrush current and protect in case of faults. When designing a hot swap, three key scenarios must be considered:

• Start-up
• Output of a hot swap is shorted to ground when the hot swap is on. This is often referred to as a hot-short.
• Powering up a board when the output and ground are shorted. This is usually called a start-into-short.

All of these scenarios place a lot of stress on the hot swap MOSFET and thus special care is required when designing the hot swap circuit to keep the MOSFET within its SOA (Safe Operating Area). Detailed design examples are provided in the following sections. Solving all of the equations by hand is cumbersome and can result in errors. Instead, TI recommends using the LM5069 Design Calculator provided on the product page.