Datasheet

11
LTC1645
1645fa
APPLICATIO S I FOR ATIO
WUUU
(a) V
CC
Short-Circuit Supply Current Glitch Without Any Limiting (b) V
CC
Supply Glitch Without Any Limiting
(c) V
CC
Short-Circuit Supply Current Glitch
with 2µH Series Inductor
(d) V
CC
Supply Glitch with 2µH Series Inductor
Figure 8. Supply Glitch
Supply Glitching
LTC1645 Hot Swap circuits on the backplane are generally
used to provide power-up/down sequence at insertion/
removal as well as overload/short-circuit protection. If a
short-circuit occurs at supply ramp-up, the circuit breaker
trips. The partially enhanced FET is easily disconnected
without any supply glitch.
If a dead short occurs after a supply connection is made
(Figure 8), the sense resistor R1 and the R
DS(ON)
of the
fully enhanced FET provide a low impedance path for
0.1µF
1645 F08
10Ω
R1
0.01Ω
12V
IRF7413
2µH
+
–
LTC1645
SUPPLY
GLITCH
BACKPLANE CONNECTOR
BOARD WITH POSSIBLE
SHORT-CIRCUIT FAULT
100µF
+
1µs/DIV
25A/DIV
1645 F08a
1µs/DIV
4V/DIV
1645 F08b
V
CC
GATE
1µs/DIV
5A/DIV
1645 F08c
1µs/DIV
4V/DIV
1645 F08d
GATE
V
CC