LTC4421 High Power Prioritized PowerPath Controller FEATURES DESCRIPTION n 0V to 36V Wide Operating Range (60V Tolerant) The LTC 4421 connects one of two input supplies to a n Drives Large External N-Channel MOSFETs for High common output based on user-defined priority and valid- Output Current Applications ity. By definition, the supply connected to V1 is the higher n Accurately Limits Inrush Current priority supply, although this can be changed dynamically. n Connects Highest Priority Valid Supply to Output Load External resistive dividers set the undervoltage and over- n Changes Channel Priority in Real Time voltage thresholds that bound the valid voltage window. n 2% OV, UV Input Comparators Strong gate drivers switch the large external N-channel n Individually Adjustable Current Limit Time-Out for MOSFETs quickly. Fast switchover circuitry minimizes Each Channel output droop when changing channels while preventing n Adjustable Input Validation Time reverse and cross conduction. A fast comparator detects n Fast Switchover Minimizes V Droop OUT input short circuits and quickly turns off the N-channel n 36-Lead 5mm 6mm QFN and SSOP Packages MOSFETs to minimize disruption. APPLICATIONS External sense resistors set the maximum inrush and cur- rent limit currents. During current limiting, the LTC4421 n High Reliability Systems controls the N-channel MOSFET gate to regulate 25mV n Server Based Back-Up Systems across the sense resistor. When the sense resistor voltage n Industrial Handheld Instruments has been regulated to 25mV for a user-settable time, the n Battery Back-Up Systems channel is disconnected and a fault is set. All registered trademarks and trademarks are the property of their respective owners. TYPICAL APPLICATION I = 10A LIM1 2.5m V OUT PRIMARY 12V 1.21 220F 1F I = 10A LIM2 2.5m SECONDARY 28V 2.8 1F 47nF 47nF 1F 1M V1 GATE1 SOURCE1 SENSE1 OUT1 CPO CPOREF V2 GATE2 SOURCE2 SENSE2 OUT2 UVF1 EXTV CC 0.1F 20k UVR1 VALID1 12.7k VALID2 OV1 CH1 DIGITAL CH2 STATUS LTC4421 35.7k 1M FAULT1 OUTPUTS FAULT2 UVF2 CASOUT 8.06k RETRY UV1FALLING = 7.81V UVR2 DISABLE1 DIGITAL UV1RISING = 11.04V DISABLE2 CONTROL 3.92k OV1RISING = 14.96V SHDN INPUTS OV2 CASIN UV2FALLING = 18.1V GND QUAL TMR1 TMR2 INTV CC UV2RISING = 25.2V 16.5k 4421 TA01 470pF 47nF 47nF 1F OV2RISING = 31.2V Rev. 0 1 Document Feedback For more information www.analog.comLTC4421 ABSOLUTE MAXIMUM RATINGS (Notes 1, 2) Supply Voltages GATE1, GATE2 (Note 3) .............................0.3V to CPO V1, V2, EXTV ........................................10V to 60V CASOUT ................................................... 0.3V to 6V CC OUT1, OUT2, CPOREF ..............................10V to 45V Output Currents Input Voltages FAULT1, FAULT2, CH1, CH2, VALID1, VALID2, DISABLE1, DISABLE2, SHDN .............. 0.3V to 60V CASOUT ...............................................................5mA CASIN ...................................................... 0.3V to 6V Operating Ambient Temperature Range SENSE1, SENSE2, SOURCE1, SOURCE2 ..10V to 45V LTC4421C ................................................ 0C to 70C UVF1, UVF2, UVR1, UVR2, OV1, OV2 .... 0.3V to 60V LTC4421I .............................................40C to 85C RETRY, TMR1, TMR2, QUAL....0.3V to INTV +0.3V LTC4421H .......................................... 40C to 125C CC Output Voltages Storage Temperature Range .................. 65C to 150C VALID1, VALID2, CH1, CH2, FAULT1, FAULT2, CPO ............................. 0.3V to 60V INTV ..................................................... 0.3V to 6V CC PIN CONFIGURATION TOP VIEW TOP VIEW 1 36 EXTV CPO CC 2 35 GND CPOREF 3 34 OUT2 OUT1 36 35 34 33 32 31 30 29 4 33 SENSE2 SENSE1 SOURCE1 1 28 SOURCE2 5 32 SOURCE2 SOURCE1 GATE1 2 27 GATE2 6 31 GATE2 GATE1 V1 3 26 V2 7 30 V2 V1 UVF1 4 25 UVF2 8 29 UVF2 UVF1 UVR1 5 24 UVR2 37 9 28 UVR2 UVR1 OV1 6 23 OV2 10 27 OV2 TMR1 7 22 TMR2 OV1 11 26 TMR2 DISABLE1 8 21 DISABLE2 TMR1 CH1 9 20 CH2 12 25 DISABLE2 DISABLE1 VALID1 10 19 VALID2 13 24 CH2 CH1 11 12 13 14 15 16 17 18 14 23 VALID2 VALID1 15 22 FAULT2 FAULT1 16 21 SHDN CASIN 17 20 RETRY INTV CC UHE PACKAGE 36-LEAD (5mm 6mm) PLASTIC QFN 18 19 QUAL CASOUT T = 150C, = 43C/W, = 5C/W JMAX JA JC G PACKAGE EXPOSED PAD (Pin 37), PCB GND CONNECTION OPTIONAL 36-LEAD PLASTIC SSOP T = 150C, = 70C/W JMAX JA Rev. 0 2 For more information www.analog.com FAULT1 SENSE1 CASIN OUT1 INTV CPOREF CC CASOUT CPO QUAL EXTV CC RETRY GND SHDN OUT2 FAULT2 SENSE2