Datasheet

Normal operating current

Charging

Bulk

Capacitors

Fault level

Circuit Breaker Turn On

TPS2363

www.ti.com

SLUS680B –JANUARY 2006–REVISED JANUARY 2010

Circuit Breaker

Circuit breaker control does not protect the system from glitches on a fault. The backplane and power system

must be designed for a higher current level. The peak current is only limited by the R

DS(on)

of the power FET

used for the hot plug. When a fault occurs there is no current limit, the fault timer controls when power is turned

off to the module. The fault time is typically set in the 10 ms range. The high current of a fault can reduce the

voltage on the backplane causing the system or other boards to go to an unknown state, the system may have to

be reset on a fault or power cycled. A fast trip mode is active if not disabled by the SMBus. When the current

draw is much higher than the fault current setting, the output is turned off immediately without waiting for the fault

timer. This reduces the chance of voltage glitches that leave the system or other modules in an unknown state.

Figure 4 shows the turn on using circuit breaker, the current goes beyond the fault level as the current ramps,

then drops back when the capacitors are charged.

Figure 4. Hot Plug Circuit Breaker Turn On

Product Folder Link(s): TPS2363