LTC4229
Ideal Diode and
Hot Swap Controller
Fea T Descrip T
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Ideal Diode and Inrush Current Control for The LTC 4229 offers ideal diode and Hot Swap functions
Redundant Supplies for a power rail by controlling two external N-channel MOS-
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Low Loss Replacement for Power Schottky Diode FETs. The MOSFET acting as an ideal diode replaces a high
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Protects Output Voltage from Input Brownouts power Schottky diode and the associated heat sink, saving
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Allows Safe Hot Swapping from a Live Backplane power and board area. The Hot Swap MOSFET control al-
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2.9V to 18V Operating Range lows a board to be safely inserted and removed from a live
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Controls Back-to-Back N-Channel MOSFETs backplane by limiting inrush current. The supply output is
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Limits Peak Fault Current in 1s also protected against short-circuit faults with a fast acting
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Adjustable Current Limit with Foldback foldback current limit and electronic circuit breaker.
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Adjustable Start-Up and Current Limit Fault Delay
The LTC4229 regulates the forward voltage drop across
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0.5s Ideal Diode Turn-On and Turn-Off Time
the external MOSFET to ensure smooth current transfer
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Undervoltage and Overvoltage Protection
in diode-OR applications. The ideal diode turns on quickly
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Status, Fault and Power Good Outputs
to reduce the load voltage droop during supply switcho-
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Pin Selectable Latch Off or Automatic Retry
ver. If the input supply fails or is shorted, a fast turn-off
After Fault
minimizes reverse-current transients.
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24-Lead 4mm 5mm QFN and SSOP Packages
The LTC4229 provides adjustable start-up delay, under-
voltage and overvoltage protection, and reports fault and
a T
power good status for the supply. It can be configured
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Redundant Power Supplies
for latch off or automatic retry after a fault.
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Supply Holdup
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot
Swap is a trademark of Linear Technology Corporation. All other trademarks are the property of
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High Availability Systems and Servers
their respective owners.
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Protected by U.S. Patents, including 7920013, 8022679.
Telecom and Network Infrastructure
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Power Prioritizer
Typical a T
Plug-In Supply Card Application
PLUG-IN
SUPPLY
Diode FET Protects Output
DIODE FET HOT SWAP FET
CARD
SiR818DP 0.0025 SiR818DP
V Voltage from Input Brownout
OUT
12V
7.6A
+
680F
IN
10 1k
0.1F
10V/DIV
10nF
OUT
10V/DIV
+
CPO DSRC IN DGATE DSNS SENSE SENSE HGATE OUT 15k
DGATE
FB 20V/DIV
2k
21.5k
HGATE
20V/DIV
UV
LTC4229
PWRGD
1.1k
4229 TA01b
FAULT
50s/DIV
OV
DSTAT
2k DFLT
DOFF GND DCFG INTV RTMR DTMR FTMR EN
CC
0.1F
0.1F
BACKPLANE
4229 TA01a
4229f
1
For more information www.linear.com/LTC4229
ion pplica
ions pplica
ion uresLTC4229
a T e Maxi Mu M r a T (Notes 1, 2)
Supply Voltages Average Currents
IN ........................................................... 0.3V to 24V FAULT, PWRGD, DSTAT, DFLT ...............................5mA
INTV ..................................................... 0.3V to 7V INTV .................................................................1mA
CC CC
Input Voltages Operating Ambient Temperature Range
FB, DCFG ................................................. 0.3V to 7V LTC4229C ................................................ 0C to 70C
FTMR, DTMR, RTMR .............0.3V to INTV + 0.3V LTC4229I .............................................40C to 85C
CC
UV, OV, EN, DOFF ................................... 0.3V to 24V Storage Temperature Range .................. 65C to 150C
+
SENSE , SENSE , DSNS, DSRC ............. 0.3V to 24V Lead Temperature (Soldering, 10 sec)
Output Voltages G Package .........................................................300C
FAULT, PWRGD, DSTAT, DFLT, OUT ........ 0.3V to 24V
CPO, DGATE (Note 3) ............................. 0.3V to 35V
HGATE (Note 4) ..................................... 0.3V to 35V
p c F T
TOP VIEW
TOP VIEW
CPO 1 24 HGATE
DGATE 2 23 OUT
24 23 22 21 20
DSRC 3 22 FB
DSRC 1 19 PWRGD
SENSE 4 21 PWRGD
SENSE 2 18 FAULT
+
SENSE 5 20 FAULT
+
SENSE
3 17 DSTAT
IN 6 19 DSTAT
25
IN 4 16 DFLT
DSNS 7 18 DFLT
DSNS 5 15 DOFF
INTV 8 17 DOFF
CC
INTV 6 14 DCFG
CC
GND 9 16 DCFG
GND 7 13 OV
8 9 10 11 12
DTMR 10 15 OV
RTMR 11 14 UV
FTMR 12 13 EN
UFD PACKAGE
24-LEAD (4mm 5mm) PLASTIC QFN
G PACKAGE
T = 125C, = 43C/W (Note 5)
24-LEAD PLASTIC SSOP
JMAX JA
EXPOSED PAD (PIN 25) PCB GND CONNECTION OPTIONAL
T = 125C, = 88C/W
JMAX JA
o r D i n F Ma T
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC4229CUFD#PBF LTC4229CUFD#TRPBF 4229 24-Lead (4mm 5mm) Plastic QFN 0C to 70C
LTC4229IUFD#PBF LTC4229IUFD#TRPBF 4229 24-Lead (4mm 5mm) Plastic QFN 40C to 85C
LTC4229CG#PBF LTC4229CG#TRPBF LTC4229G 24-Lead Plastic SSOP 0C to 70C
LTC4229IG#PBF LTC4229IG#TRPBF LTC4229G 24-Lead Plastic SSOP 40C to 85C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to: