LTC4234 20A Guaranteed SOA Hot Swap Controller FEATURES DESCRIPTION n Allows Safe Board Insertion into Live Backplane The LTC 4234 is an integrated solution for Hot Swap n Small Footprint applications that allows a board to be safely inserted and n removed from a live backplane. The part integrates a 4m MOSFET Including R SENSE n HotSwap controller, power MOSFET and current sense Safe Operating Area Guaranteed at 81W, 30ms n resistor in a single package for small form factor applica- Wide Operating Voltage Range: 2.9V to 15V n tions. The MOSFET Safe Operating Area is production tested Adjustable, 11% Accurate Current Limit n and guaranteed for the stresses in Hot Swap applications. Current and Temperature Monitor Outputs n Overtemperature Protection The LTC4234 provides separate inrush current control n Adjustable Current Limit Timer Before Fault and an 11% accurate 22.5A current limit with output n Power Good and Fault Outputs dependent foldback. The current limit threshold can be n Adjustable Inrush Current Control adjusted dynamically using the I pin. Additional features SET n 2.5% Accurate Undervoltage and Overvoltage Protection include a current monitor output that amplifies the sense n Pin Compatible with LTC4233 resistor voltage for ground referenced current sensing n Available in a 38-Pin (5mm 9mm) QFN Package and a MOSFET temperature monitor output. Thermal limit, overvoltage, undervoltage and power good monitoring are also provided. For a 10A compatible version, see LTC4233. APPLICATIONS L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and n HotSwap and PowerPath are trademarks of Linear Technology Corporation. All other High Availability Servers trademarks are the property of their respective owners. n Solid State Drives n Industrial n 240W, 12V Systems TYPICAL APPLICATION 12V, 20A Card Resident Application with Auto-Retry V OUT Power-Up Waveform 12V V OUT 12V DD + 20A 150k * 1000F 107k FB UV V IN CONTACT 10V/DIV 20k BOUNCE 10k FLT I 5.23k LTC4234 IN 0.2A/DIV OV PG 10k SENSE GATE V OUT SENSE 10V/DIV I TIMER SET PG INTV I ADC 10V/DIV MON CC 1F GND 20k 4234 TA01a 4234 TA01b 20ms/DIV *TVS: DIODES INC. SMAJ17A 4234fa 1 For more information www.linear.com/LTC4234LTC4234 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Notes 1, 2) TOP VIEW Supply Voltage (V ) ................................. 0.3V to 28V DD Input Voltages UV 1 38 I SET FB, OV, UV ..............................................0.3V to 12V OV 2 37 FB 39 I 3 36 FLT TIMER ................................................... 0.3V to 3.5V MON V DD TIMER 4 35 PG SENSE , SENSE .....V 10V or 0.3V to V + 0.3V DD DD INTV 5 34 SENSE CC Output Voltages V (DNC) 6 33 V (DNC) DD DD I , I ................................................. 0.3V to 3V SET MON GND GATE 7 32 PG, FLT ................................................. 0.3V to 35V SENSE (DNC) 8 31 SENSE OUT ............................................ 0.3V to V + 0.3V DD OUT 9 30 OUT INTV .................................................. 0.3V to 3.5V OUT OUT CC 10 29 40 GATE (Note 3) ........................................ 0.3V to 33V OUT 11 28 OUT SENSE OUT OUT 12 27 Operating Ambient Temperature Range OUT OUT 13 26 LTC4234C ................................................ 0C to 70C OUT 14 25 OUT LTC4234I .............................................40C to 85C OUT OUT 15 24 LTC4234H .......................................... 40C to 125C OUT OUT 16 23 Junction Temperature (Notes 4, 5) ........................ 150C 17 18 19 20 21 22 Storage Temperature Range .................. 65C to 150C WHH PACKAGE 38-LEAD (5mm 9mm) PLASTIC QFN T = 150C, = 15C/W JMAX JA EXPOSED PADS (PINS 39 and 40) ARE V AND SENSE DD = 15C/W SOLDERED, OTHERWISE = 50C/W JA JA ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC4234CWHH PBF LTC4234CWHH TRPBF 4234 38-Lead (5mm 9mm) Plastic QFN 0C to 70C LTC4234IWHH PBF LTC4234IWHH TRPBF 4234 38-Lead (5mm 9mm) Plastic QFN 40C to 85C LTC4234HWHH PBF LTC4234HWHH TRPBF 4234 40C to 125C 38-Lead (5mm 9mm) Plastic QFN 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: