LTC1642A
Hot Swap Controller
FEATURES
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DESCRIPTIO
Adjustable Undervoltage and Overvoltage
Protection
Foldback Current Limit
Adjustable Current Limit Time-Out
V
CC
: 2.97V to 16.5V Normal Operation, Protected
Against Surges to 33V
Single Channel NFET Driver
Latch Off or Automatic Retry on Current Fault
Driver for SCR Crowbar on Overvoltage
Adjustable Reset Timer
Reference Output with Uncommitted Comparator
16-Pin SSOP Package
The LTC
®
1642A is a 16-pin Hot Swap
TM
controller that
allows a board to be safely inserted and removed from a
live backplane. Using an external N-Channel pass transis-
tor, the board supply voltage can be ramped up at an
adjustable rate. A high side switch driver controls the
N-Channel gate for supply voltages ranging from 2.97V
to 16.5V.
The SENSE pin allows foldback limiting of the load current,
with circuit breaker action after an adjustable delay time.
The delay allows the part to power-up in current limit. The
CRWBR output can be used to trigger an SCR for crowbar
protection of the load if the input supply exceeds an
adjustable threshold. The RESET output can generate a
system reset with adjustable delay when the supply volt-
age falls below an adjustable threshold. The ON pin cycles
the board power. The LTC1642A is available in the 16-pin
SSOP package.
, LTC and LT are registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners. Hot Swap is a trademark of Linear
Technology Corporation.
APPLICATIO S
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Hot Board Insertion
Electronic Circuit Breaker
InfiniBand
TM
Systems
TYPICAL APPLICATIO
BACKPLANE
12V
PLUG-IN CARD
0.010Ω
5%
FDS6630A
(SHORT PIN)
110k
1%
1N4705
18V
100Ω
5%
330Ω
5%
0.047µF
107k
1%
V
CC
SENSE
GATE
RESET
FB
CRWBR
COMP
–
COMP
+
UV = 10.8V
2.87k
1%
OV = 13.2V
11.3k
1%
ON
FAULT
OV
GND BRK TMR
LTC1642A
2N2222
13k
1%
COMPOUT
RST TMR
REF
0.33µF
GND
0.33µF
0.1µF
0.01µF
1642a TA01
U
+
12V
AT 2.5A
C
LOAD
POWER-GOOD = 11.4V
MCR
12DC
1642af
U
U
1
LINER [ LINEAR TECHNOLOGY ]
