LTC4228-1/LTC4228-2 Dual Ideal Diode and Hot Swap Controller Fea T Descrip T n The LTC 4228 offers ideal diode and Hot Swap functions Power Path and Inrush Current Control for for two power rails by controlling two external N-channel Redundant Supplies n MOSFETs in each rail. MOSFETs acting as ideal diodes re- Low Loss Replacement for Power Schottky Diodes n place two high power Schottky diodes and the associated Protects Output Voltage from Input Brownouts n heat sinks, saving power and board area. Hot Swap control Allows Safe Hot Swapping from a Live Backplane n MOSFETs allow boards to be safely inserted and removed 2.9V to 18V Operating Range n from a live backplane by limiting inrush current. The supply Controls N-Channel MOSFETs n output is also protected against short-circuit faults with a Limits Peak Fault Current in 1s n fast acting current limit and internal timed circuit breaker. Adjustable Current Limit with Circuit Breaker n Adjustable Current Limit Fault Delay The LTC4228 regulates the forward voltage drop across n Smooth Switchover without Oscillation the external MOSFETs and sense resistor to ensure smooth n 0.5s Ideal Diode Turn-On and Turn-Off Time current transfer from one supply to the other without n Status, Fault and Power Good Outputs oscillation. The ideal diodes turn on quickly to reduce n LTC4228-1: Latch Off After Fault the load voltage droop during supply switch-over. If the n LTC4228-2: Automatic Retry After Fault input supply fails or is shorted, a fast turn-off minimizes n 28-Lead 4mm 5mm QFN and SSOP Packages reverse-current transients. The LTC4228 allows independent on/off control, and reports a T fault and power good status for the supply. The LTC4228 n Redundant Power Supplies improves on the LTC4225 by recovering more quickly from n MicroTCA Systems and Servers input brownouts to preserve the output voltage. n Telecom Networks 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 n Power Prioritizer trademarks are the property of their respective owners. Typical a T TCA Application PLUG-IN CARD 1 Smooth Supply Switchover Si7336ADP Si7336ADP 0.004 12V 12V 7.6A 0.1F + CPO1 IN1 DGATE1 SENSE1 SENSE1 HGATE1 OUT1 IN1 1V/DIV STATUS1 FAULT1 137k IN2 PWRGD1 ON1 1V/DIV EN1 47nF 20k TMR1 I IN1 INTV CC LTC4228 2A/DIV 0.1F PLUG-IN 47nF TMR2 GND CARD 2 EN2 20k PWRGD2 I IN2 ON2 FAULT2 2A/DIV STATUS2 137k + CPO2 IN2 DGATE2 SENSE2 SENSE2 HGATE2 OUT2 422512 TA01b 200ms/DIV 0.1F 12V 12V 7.6A Si7336ADP 0.004 Si7336ADP BACKPLANE 422812 TA01a 422812f 1 ion pplica ions pplica ion uresLTC4228-1/LTC4228-2 a Te Maxi Mu M r a T (Notes 1, 2) Supply Voltages HGATE1, HGATE2 (Note 4) ..................... 0.3V to 35V IN1, IN2 .................................................. 0.3V to 24V OUT1, OUT2 ........................................... 0.3V to 24V INTV ..................................................... 0.3V to 7V Average Currents CC Input Voltages FAULT1, FAULT2, PWRGD1, PWRGD2 ...................5mA ON1, ON2, EN1, EN2............................... 0.3V to 24V STATUS1, STATUS2 ..............................................5mA TMR1, TMR2 .........................0.3V to INTV + 0.3V INTV .................................................................1mA CC CC + + SENSE1 , SENSE2 ................................ 0.3V to 24V Operating Temperature Range SENSE1 , SENSE2 ................................ 0.3V to 24V LTC4228C ................................................ 0C to 70C Output Voltages LTC4228I .............................................40C to 85C FAULT1, FAULT2, PWRGD1, PWRGD2 ..... 0.3V to 24V Storage Temperature Range .................. 65C to 150C STATUS1, STATUS2 ................................ 0.3V to 24V Lead Temperature (Soldering, 10 sec) CPO1, CPO2 (Note 3) ............................. 0.3V to 35V GN Package ......................................................300C DGATE1, DGATE2 (Note 3) ..................... 0.3V to 35V p in c F T TOP VIEW TOP VIEW STATUS1 1 28 HGATE1 CPO1 2 27 OUT1 DGATE1 3 26 PWRGD1 28 27 26 25 24 23 SENSE1 4 25 FAULT1 SENSE1 1 22 FAULT1 + + SENSE1 2 21 ON1 SENSE1 5 24 ON1 IN1 3 20 EN1 IN1 6 23 EN1 INTV 4 19 TMR1 CC INTV 7 22 TMR1 CC 29 GND 5 18 TMR2 GND 8 21 TMR2 IN2 6 17 EN2 IN2 9 20 EN2 + SENSE2 7 16 ON2 + SENSE2 10 19 ON2 SENSE2 8 15 FAULT2 SENSE2 11 18 FAULT2 9 10 11 12 13 14 DGATE2 12 17 PWRGD2 CPO2 13 16 OUT2 STATUS2 14 15 HGATE2 UFD PACKAGE GN PACKAGE 28-LEAD (4mm 5mm) PLASTIC QFN 28-LEAD PLASTIC SSOP NARROW T = 125C, = 43C/W (NOTE 5) JMAX JA T = 125C, = 80C/W EXPOSED PAD (PIN 29) PCB GND CONNECTION OPTIONAL JMAX JA 422812f 2 DGATE2 DGATE1 CPO2 CPO1 STATUS2 STATUS1 HGATE2 HGATE1 OUT2 OUT1 PWRGD2 PWRGD1 ion igura on ings bsolu