LTC4211
Hot Swap Controller with
Multifunction Current Control
FEATURES
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DESCRIPTIO
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Allows Safe Board Insertion and Removal
from a Live Backplane
Controls Supply Voltages from 2.5V to 16.5V
Programmable Soft-Start with Inrush Current
Limiting, No External Gate Capacitor Required
Faster Turn-Off Time Because No External Gate
Capacitor is Required
Dual Level Overcurrent Fault Protection
Programmable Response Time for Overcurrent
Protection (MS)
Programmable Overvoltage Protection (MS)
Automatic Retry or Latched Mode Operation (MS)
High Side Drive for an External N-Channel FET
User-Programmable Supply Voltage Power-Up Rate
FB Pin Monitors V
OUT
and Signals RESET
Glitch Filter Protects Against Spurious RESET Signal
The LTC
®
4211 is a Hot Swap
TM
controller that allows a
board to be safely inserted and removed from a live
backplane. An internal high side switch driver controls the
gate of an external N-channel MOSFET for supply voltages
ranging from 2.5V to 16.5V. The LTC4211 provides soft-
start and inrush current limiting during the start-up period
which has a programmable duration.
Two on-chip current limit comparators provide dual level
overcurrent circuit breaker protection. The slow com-
parator trips at V
CC
– 50mV and activates in 20µs (or
programmed by an external filter capacitor, MS only). The
fast comparator trips at V
CC
– 150mV and typically
responds in 300ns.
The FB pin monitors the output supply voltage and signals
the RESET output pin. The ON pin signal turns the chip on
and off and can also be used for the reset function. The
MS package has FAULT and FILTER pins to provide
additional functions like fault indication, autoretry or
latch-off modes, programmable current limit response
time and programmable overvoltage protection using an
external Zener diode clamp.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
APPLICATIO S
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Electronic Circuit Breaker
Hot Board Insertion and Removal (Either On
Backplane or On Removable Card)
Industrial High Side Switch/Circuit Breaker
TYPICAL APPLICATIO
BACKPLANE PCB EDGE
CONNECTOR CONNECTOR
(FEMALE)
(MALE)
V
CC
5V
LONG
Single Channel 5V Hot Swap Controller
Power-Up Sequence
R
SENSE
0.007Ω
R
X
10Ω
C
X
100nF
M1
Si4410DY
+
C
LOAD
8
V
CC
7
SENSE
6
GATE
FB
5
R3
36k
R4
15k
RESET
TIMER
GND
C
TIMER
10nF
4
3
1
R5
10k
µP
LOGIC
RESET
V
OUT
5V
5A
V
GATE
5V/DIV
Z1*
SHORT
R1
20k
R2
10k
2
ON
LTC4211
GND
PCB CONNECTION SENSE
LONG
Z1 = 1SMA10A OR SMAJ10A
* OPTIONAL
GND
4211 TA01A
U
NO C
LOAD
V
RESET
5V/DIV
V
ON
1V/DIV
V
TIMER
1V/DIV
2.5ms/DIV
4211 TA01b
U
U
4211f
1
LINER [ LINEAR TECHNOLOGY ]
