LTC3643IUDD#PBF

LTC3643 2A Bidirectional Power Backup Supply FEATURES DESCRIPTION n Bidirectional Synchronous Boost Capacitor The LTC 3643 is a bidirectional synchronous step- Charger/Buck Regulator for System Backup up charger and step-down converter which efficiently n Wide Input Voltage Range: 3V to 17V charges a capacitor array up to 40V from an input supply n Up to 40V Capacitor Voltage Storage for High between 3V to 17V. When the input supply falls below the Energy Backup programmable power-fail threshold, the step-up charger n 2A Maximum CAP Charge Current operates in reverse as a synchronous step-down regulator n Integrated Power N-Channel MOSFETs to power the system rail from the backup capacitor during (150m Top and 75m Bottom) this power interruption/failure condition. n Integrated Power N-Channel MOSFET for Output/CAP When charging the backup capacitor, an external low- Disconnect (50m) value sense resistor may be used to maintain an accu- n Input Current Limit During Charging rate current limit from the input supply or implement n Fast 1MHz Switching Frequency PowerPath functionality. n 1% Reference Accuracy for System Voltage Regulation n The step-down converter operates at a 1MHz switching Indicator Outputs for Charge Status and Input Power Fail n frequency, allowing small external components to be Low Profile 24-lead 3mm 5mm QFN Package used. Low quiescent current during regulation maximizes the energy usage from the backup capacitor. APPLICATIONS L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks and PowerPath is trademarks of Analog Devices, Inc. All other trademarks are the property of n Backup Capacitor Systems their respective owners. Protected by U.S. Patents. Including 5481178, 6580258, 6498466, n 6611131, 5705919. Power Failure Backup Systems n Solid-State Drives TYPICAL APPLICATION Approximate Charge/Backup Time per 40V Backup System Regulating System Supply to 5V 1mF of Storage Cap (40V Backup) 500 0.01 POWER CHARGE TIME SUPPLY 0.1F BACKUP TIME WITH 2A LOAD 4.7H 47F BACKUP TIME WITH 1A LOAD SYSTEM LOAD 400 BACKUP TIME WITH 0.5A LOAD CLP V INDIS SW BOOST IN 40V BACKUP 300 GATE CAP + 22F INTV 35.7k CC RUN 1mF 4.7F 200 PFI 392k LTC3643 ENERGY 44.2k FBCAP 100 STORAGE FBSYS 6.04k 12.1k 6.04k ITH 0 CAPGD 3 6 9 12 15 400k 22pF PFO SYSTEM LOAD VOLTAGE (V) GND 470pF 3643 TA01b 3643 TA01a 3643fc 1 For more information www.linear.com/LTC3643 CHARGE/BACKUP TIME (ms)LTC3643 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) V ............................................................. 0.3V to 17V IN TOP VIEW RUN .................................................. 0.3V to V +0.3V IN CLP ............................................................ 0.3V to 17V CAP ............................................................ 0.3V to 42V 24 23 22 21 BOOST-SW ................................................... 0.3V to 4V PGND 1 20 SW PGND 2 SW INTV , FBSYS, FBCAP ................................ 0.3V to 4V 19 CC CAP 3 18 SW PFI ............................................................... 0.3V to 4V V 4 17 INDIS IN 25 I .............................................0.3V to V +0.3V LIM INTVCC SGND V 5 16 INDIS IN PFO, CAPGD ................................................ 0.3V to 6V GATE 6 15 BOOST Operating Junction Temperature Range RUN 7 INTV 14 CC (Note 2) ............................................. 40C to 125C FBSYS 8 13 PFI Storage Temperature Range .................. 65C to 150C 9 10 11 12 Lead Temperature (Soldering, 10sec).................... 260C UDD PACKAGE 24-LEAD (3mm 5mm) PLASTIC QFN T = 125C, = 46C/W, = 5.0C/W JMAX JA JC EXPOSED PAD (PIN 25) IS SGND, MUST BE SOLDERED TO PCB