LTC4236
Dual Ideal Diode-OR and
Single Hot Swap Controller
with Current Monitor
Fea T Descrip T
n
Ideal Diode-OR and Inrush Current Control for The LTC 4236 offers ideal diode-OR and Hot Swap func-
Redundant Supplies tions for two power rails by controlling external N-channel
n
MOSFETs. MOSFETs acting as ideal diodes replace two
Low Loss Replacement for Power Schottky Diodes
n
high power Schottky diodes and the associated heat sinks,
Enables Safe Board Insertion into a Live Backplane
n saving power and board area. A Hot Swap control MOSFET
2.9V to 18V Operating Range
n allows a board to be safely inserted and removed from a
Current Monitor Output
n live backplane by limiting inrush current. The supply output
Controls N-Channel MOSFETs
is also protected against short-circuit faults with a fast
n
Limits Peak Fault Current in 1s
acting foldback current limit and electronic circuit breaker.
n
Adjustable Current Limit with Foldback
n
Adjustable Start-Up and Current Limit Fault Delay
The LTC4236 regulates the forward voltage drop across
n
0.5s Ideal Diode Turn-On and Turn-Off Time
the ideal diode MOSFETs to ensure smooth current transfer
n
Smooth Switchover without Oscillation
from one supply to the other without oscillation. The ideal
n
Fault, Power Good and Diode Status Outputs
diode MOSFETs turn on quickly to reduce the load voltage
n
LTC4236-1: Latch Off After Fault
droop during supply switchover. If the input supply fails
n
LTC4236-2: Automatic Retry After Fault or is shorted, a fast turn-off minimizes reverse current
n
28-Pin 4mm x 5mm QFN Package transients.
A current sense amplifier translates the voltage across the
sense resistor to a ground referenced signal. The LTC4236
a T
provides adjustable start-up delay, turn-on/-off control,
n
Redundant Power Supplies
and reports fault and power good status for the supply.
n
High Availability Systems and Servers
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
n Technology Corporation. All other trademarks are the property of their respective owners.
Telecom and Network Infrastructure
Protected by U.S. Patents, including 7920013, 8022679.
Typical a T
Ideal Diode-OR with Hot Swap Application
Smooth Supply Switchover
SiR158DP
12V
IN2
0.1F
SiR158DP 0.003 SiR158DP
12V
IN1
12V
7A
+ IN1
1V/DIV
0.1F
0.1F
C
LOAD
IN2
1V/DIV
+ +
13.7k
CPO1 IN1 DGATE1 CPO2 D2SRC IN2 DGATE2 REG SENSE CS SENSE HGATE OUT 15k
I
IN1
ON
FB
2A/DIV
2k 2k
I
IN2
2A/DIV
LTC4236
FAULT
PWRGD
4236 TA01b
DSTAT1
EN 200ms/DIV
DSTAT2
IMON ADC
INTV
CC GND D2OFF DTMR FTMR
0.1F 0.1F 0.1F
4236 TA01a
4236f
1
For more information www.linear.com/LTC4236
ion pplica
ions pplica
ion uresLTC4236
a T e Maxi Mu M r a T p c F T
(Notes 1, 2)
Supply Voltages
TOP VIEW
IN1, IN2 .................................................. 0.3V to 24V
INTV ..................................................... 0.3V to 7V
CC
+ +
REG ...........................SENSE 5V to SENSE + 0.3V
28 27 26 25 24 23
Input Voltages
SENSE 1 22 FAULT
+
ON, D2OFF, EN ...................................... 0.3V to 24V SENSE
2 21 DSTAT1
+
CS 3 20 DSTAT2
FTMR, DTMR .........................0.3V to INTV + 0.3V
CC
IN1 4 19 ON
FB ............................................................ 0.3V to 7V
29
INTV 5 18 D2OFF
+ +
CC
SENSE , SENSE , CS , D2SRC .............. 0.3V to 24V
GND 6 17 NC
Output Voltages
IN2 7 16
NC
IMON ....................................................... 0.3V to 7V
D2SRC 8 15 REG
FAULT, PWRGD, DSTAT1, DSTAT2 ........... 0.3V to 24V
9 10 11 12 13 14
CPO1, CPO2 (Notes 3, 4) ....................... 0.3V to 35V
DGATE1, DGATE2 (Notes 3, 4) ............... 0.3V to 35V
UFD PACKAGE
HGATE (Note 5) ..................................... 0.3V to 35V
28-LEAD (4mm 5mm) PLASTIC QFN
T = 125C, = 43C/W (NOTE 6)
OUT ....................................................... 0.3V to 24V JMAX JA
EXPOSED PAD (PIN 29) PCB GND CONNECTION OPTIONAL
Average Currents
FAULT, PWRGD, DSTAT1, DSTAT2 .........................5mA
INTV ...............................................................10mA
CC
Operating Ambient Temperature Range
LTC4236C ................................................ 0C to 70C
LTC4236I .............................................40C to 85C
Storage Temperature Range .................. 65C to 150C
o r D i n F Ma T
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC4236CUFD-1#PBF LTC4236CUFD-1#TRPBF 42361 28-Lead (4mm x 5mm) Plastic QFN 0C to 70C
LTC4236CUFD-2#PBF LTC4236CUFD-2#TRPBF 42362 28-Lead (4mm x 5mm) Plastic QFN 0C to 70C
LTC4236IUFD-1#PBF LTC4236IUFD-1#TRPBF 42361 28-Lead (4mm x 5mm) Plastic QFN 40C to 85C
LTC4236IUFD-2#PBF LTC4236IUFD-2#TRPBF 42362 28-Lead (4mm x 5mm) Plastic QFN 40C to 85C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
For more information on lead free part marking, go to: