LTC4214-1/LTC4214-2
Negative Low Voltage
Hot Swap Controllers
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DESCRIPTIO
FEATURES
The LTC®4214 negative voltage Hot SwapTM controller
allows a board to be safely inserted and removed from a
livebackplane.Outputcurrentiscontrolledbythreestages
of current limiting: a timed circuit breaker, active current
limiting and a fast feedforward path that limits peak
current under worst-case catastrophic fault conditions.
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Allows Safe Board Insertion and Removal from a
Live Backplane
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Controls Supplies from 0V to –16V
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Adjustable Analog Current Limit With Circuit
Breaker Timer
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Fast Response Time Limits Peak Fault Current
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Adjustable Soft-Start Current Limit
Adjustable undervoltage and overvoltage detectors dis-
connect the load whenever the input supply exceeds the
desired operating range. The LTC4214 controls negative
supplies ranging from near zero to –16V. A multifunction
timerdelaysinitialstart-upandcontrolsthecircuitbreaker’s
response time. This response time is accelerated by
sensing excessive MOSFET drain voltage, keeping the
MOSFET within its safe operating area (SOA). An adjust-
able soft-start circuit controls MOSFET inrush current at
start-up. A power good status output can enable a power
module at start-up or disable it if the circuit breaker trips.
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Adjustable Timer with Drain Voltage Accelerated
Response
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Adjustable Undervoltage/Overvoltage Protection
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LTC4214-1: Latch Off After Fault
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LTC4214-2: Automatic Retry After Fault
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Available in the 10-Pin MSOP Package
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APPLICATIO S
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Hot Board Insertion
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Electronic Circuit Breaker
The LTC4214-1 latches off after a circuit breaker fault times
out. The LTC4214-2 provides automatic retry after a fault.
The LTC4214 is available in the 10-pin MSOP package.
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Negative Power Supply Control
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Central Office Switching
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High Availability Servers
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
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Disk Arrays
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Optical Networking/Switching
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ECL
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TYPICAL APPLICATIO
–5.2V/5A ECL Supply Hot Swap Controller
Start-Up Behavior
3.3V
EN
2k
BSS138
GND
GND
GATE
+
10Ω
470Ω
5V/DIV
C
LOAD
SMAJ7A
100µF
100nF
–5.2V
ECL
1
GND
SENSE
20mV/DIV
V
IN
LTC4214-1
PWRGD
0.1µF
22Ω
(SHORT PIN)
34k
1%
2
7
6
4
75k
9, 8
10
3
UV/OV
TIMER
SS
DRAIN
GATE
V
OUT
32.4k
1%
5V/DIV
IRF7413
5.6nF
SENSE
V
EE
10Ω
10nF
0.01Ω
PWRGD
5V/DIV
PUSH
RESET
1nF
5
3.3nF
4214 TA02
4214 TA01
–5.2V
421412f
1