Minimize Short-Circuit Current Pulse in Hot-Swap Controller

Abstract: Because of internal circuit-breaker delay and limited MOS-gate pulldown current, many hot-swap controllers do not limit current during the first 10µs to 50µs following a shorted output. The result can be a brief flow of several hundred amperes. A simple external circuit counters this problem by minimizing the initial current spike and terminating the short circuit within 200ns to 500ns.
Maxim > App Notes > AMPLIFIER AND COMPARATOR CIRCUITS CIRCUIT PROTECTION
HOT-SWAP AND POWER SWITCHING CIRCUITS

Keywords: hot-swap controllers, inrush current, circuit protection, short-circuit current Aug 27, 2004

APPLICATION NOTE 3328
Minimize Short-Circuit Current Pulse in Hot-Swap Controller

Abstract: Because of internal circuit-breaker delay and limited MOS-gate pulldown current, many hot-swap
controllers do not limit current during the first 10s to 50s following a shorted output. The result can be a
brief flow of several hundred amperes. A simple external circuit counters this problem by minimizing the initial
current spike and terminating the short circuit within 200ns to 500ns.


A typical +12V, 6A, hot-swap controller circuit (Figure 1) contains (like