LTC4227
Dual Ideal Diode and
Single Hot Swap Controller
FeaT DescripT
n
Power Path and Inrush Current Control for The LTC 4227 offers ideal diode-OR and Hot Swap
Redundant Supplies functions for two power rails by controlling external N-
n
Low Loss Replacement for Power Schottky Diodes channel MOSFETs. MOSFETs acting as ideal diodes replace
n
Allows Safe Hot Swapping from a Live Backplane two high power Schottky diodes and the associated heat
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2.9V to 18V Operating Range sinks, saving power and board area. A Hot Swap control
n
Controls N-Channel MOSFETs MOSFET allows a board to be safely inserted and removed
n
Limits Peak Fault Current in 1s from a live backplane by limiting inrush current. The supply
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0.5s Ideal Diode Turn-On and Reverse Turn-Off Time output is also protected against short-circuit faults with a
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Adjustable Current Limit with Circuit Breaker fast acting current limit and internal timed circuit breaker.
n
Smooth Switchover without Oscillation
The LTC4227 regulates the forward voltage drop across
n
Adjustable Current Limit Fault Delay
the MOSFETs to ensure smooth current transfer from one
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Fault and Power Status Output
supply to the other without oscillation. The ideal diodes
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20-Lead 4mm 5mm QFN and 16-Lead SSOP Packages
turn on quickly to reduce the load voltage droop during
supply switchover. If the input supply fails or is shorted,
Ta
a fast turn-off minimizes reverse-current transients.
n
Redundant Power Supplies and Supply Holdup
The LTC4227 allows turn-on/off control, and reports fault
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Computer Systems and Servers
and power good status for the supply.
n
Telecom Networks
PART OVERCURRENT FAULT START-UP DELAY
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. Hot Swap is a trademark of Linear Technology Corporation. All other
LTC4227-1 LATCH OFF 100ms
trademarks are the property of their respective owners.
LTC4227-2 RETRY 100ms
LTC4227-3 LATCH OFF 1.6ms
LTC4227-4 RETRY 1.6ms
Typical Ta
Diode-OR with Hot Swap Application
SiR462DP Smooth Supply Switchover
12V
0.1F
SiR462DP 0.006 Si7336ADP
12V
12V
7.6A
+
0.1F
100F
IN1
1V/DIV
+
137k
CPO1 IN1 DGATE1 CPO2 IN2 DGATE2 SENSE SENSE HGATE OUT IN2
1V/DIV
ON
I
IN1
FAULT
20k
2A/DIV
LTC4227
PWRGD
I
IN2
2A/DIV
EN
INTV
CC D2ON GND TMR
4227 TA01b
4227 TA01a
200ns/DIV
0.1F 0.1F
BACKPLANE CARD
CONNECTOR CONNECTOR
422712fa
1
For more information www.linear.com/LTC4227
ion pplica
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ion uresLTC4227
Ta e MaxiMMu Tar (Notes 1, 2)
Supply Voltages HGATE (Note 4) ..................................... 0.3V to 35V
IN1, IN2 .................................................. 0.3V to 24V OUT ....................................................... 0.3V to 24V
INTV ..................................................... 0.3V to 7V Average Currents
CC
Input Voltages FAULT, PWRGD ....................................................5mA
ON, EN, D2ON ....................................... 0.3V to 24V INTV .................................................................1mA
CC
TMR .......................................0.3V to INTV + 0.3V Operating Temperature Range
CC
+
SENSE , SENSE ................................... 0.3V to 24V LTC4227C ................................................ 0C to 70C
Output Voltages LTC4227I .............................................40C to 85C
FAULT, PWRGD ...................................... 0.3V to 24V Storage Temperature Range .................. 65C to 150C
CPO1, CPO2 (Note 3) ............................. 0.3V to 35V Lead Temperature (Soldering, 10 sec)
DGATE1, DGATE2 (Note 3) ..................... 0.3V to 35V GN Package ......................................................300C
p Fc T
TOP VIEW
TOP VIEW
20 19 18 17
DGATE1 1 16 CPO1
1 16 NC
SENSE
SENSE 2 15 HGATE
+
SENSE 2 15 ON +
SENSE 3 14 OUT
IN1 3 14 EN
IN1 4 13 ON
21
INTV 4 13 TMR
CC
INTV 5 12 TMR
CC
GND 5 12 D2ON
GND 6 11 D2ON
6 11 FAULT
IN2
IN2 7 10 PWRGD
7 8 9 10
DGATE2 8 9 CPO2
GN PACKAGE
16-LEAD PLASTIC SSOP NARROW
UFD PACKAGE
T = 125C, = 110C/W
JMAX JA
20-LEAD (4mm 5mm) PLASTIC QFN
T = 125C, = 34C/W
JMAX JA
EXPOSED PAD (PIN 21) PCB GND CONNECTION OPTIONAL
422712fa
2
For more information www.linear.com/LTC4227
DGATE2 DGATE1
CPO2 CPO1
NC HGATE
OUT
PWRGD
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