LTC4041 2.5A Supercapacitor Backup Power Manager FEATURES DESCRIPTION n 2.5A Step-Down Supercapacitor Charger and 2.5A The LTC 4041 is a complete supercapacitor backup sys- Step-Up Backup Supply tem for 2.9V to 5.5V supply rails. It contains a high cur- n 6.5A Switches for 2.5A Backup from One rent step-down DC/DC converter to charge a single super- Supercapacitor or Two in Series capacitor or two supercapacitors in series. When input n Input Current Limit Prioritizes Load over power is unavailable, the step-down regulator operates ChargeCurrent in reverse as a step-up regulator to backup the system n Input Disconnect Switch Isolates Input During Backup output from the supercapacitor(s). n Automatic Seamless Switch-Over to Backup Mode The LTC4041s adjustable input current limit function n Internal Supercapacitor Balancer (No External reduces charge current to protect the input supply from Resistors) overload while an external disconnect switch isolates the n Programmable Charge Current and Charge Voltage input supply during backup. When the input supply drops n Input Power Fail Indicator below the adjustable PFI threshold, the 2.5A boost regula- n System Power Good Indicator tor delivers power from the supercapacitor to the system n Optional OVP Circuitry Protects Device to >60V output. n Constant Frequency Operation n An optional input overvoltage protection (OVP) circuit Thermally Enhanced 24-Lead 4mm 5mm protects the LTC4041 from high voltage damage at the V QFN Package IN pin. An internal supercapacitor balancing circuit maintains APPLICATIONS equal voltages across each supercapacitor and limits the maximum voltage of each supercapacitor to a pre-deter- n Ride-Through Dying Gasp Supplies mined value. The LTC4041 is available in a low profile n High Current Ride-Through 3V to 5V UPS (0.75mm) 24-Lead 4mm 5mm QFN package. n Power Meters/Industrial Alarms All registered trademarks and trademarks are the property of their respective owners. Protected n Servers/Solid State Drives by U.S. Patents, including 6522118, 6570372, 6700364, 8139329. TYPICAL APPLICATION Single Supercapacitor 3.3V Backup Application Complete Backup Event with a Single 10F Supercapacitor 3.3V 3.3V 12m INPUT SYSTEM V SYSGD 2.2F 100F SUPPLY OUTPUT 1.07M 2V/DIV P = 3.3W = 3.3V 1A BACKUP 0V V CLN IGATE V IN SYS 340k C = 100F SYS OVSNS BSTFB V SYS 121k 1V/DIV PFI RSTFB 2.2H V IN PFO SW 75k 1V/DIV SUPERCAP SYSGD SCAP LTC4041 V 10F SCAP 1V/DIV 3.8 seconds CAPGD 698k 0V IMON CAPFLT CAPFB 4041 TA01b 600ms/DIV CHGEN BSTEN GND CAPSEL CPF PROG 348k PINS NOT USED 1nF 1k IN THIS CIRCUIT: BAL 4041 TA01a Rev A 1 Document Feedback For more information www.analog.comLTC4041 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V (Transient) t < 1ms, Duty Cycle < 1% ..... 0.3V to 7V IN V (Steady State), SCAP, BAL, CLN, IN V , BSTFB, PFI, CPF, CAPFB, CAPFLT, SYS 24 23 22 21 20 V 1 19 PFI PFO, SYSGD, OVSNS, IMON ............................0.3V to 6V SYS PROG 2 18 BSTFB BSTEN, CHGEN, CAPGD, RSTFB, IMON 3 17 CPF CAPSEL ........... 0.3V to Max (V , V , V ) +0.3V 25 IN SCAP SYS CHGEN 4 16 OVSNS GND I .................................................................. 10mA BSTEN 5 15 IGATE OVSNS V 6 14 PFO IN I , I , I ...............................................10mA CAPGD PFO SYSGD CLN 7 13 CAPGD I ....................................................................1.1mA PROG 8 9 10 11 12 Operating Junction Temperature Range (Notes 2, 3) ............................................ 40C to 125C UFD PACKAGE Storage Temperature Range .................. 65C to 150C 24-LEAD (4mm 5mm) PLASTIC QFN T = 125C, = 43C/W, = 3.4C/W JMAX JA JC EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC4041EUFD PBF LTC4041EUFD TRPBF 4041 24-Lead (4mm 5mm 0.75mm) 40C TO 125C Plastic QFN LTC4041IUFD PBF LTC4041IUFD TRPBF 4041 24-Lead (4mm 5mm 0.75mm) 40C TO 125C Plastic QFN Consult ADI Marketing for parts specified with wider operating temperature ranges. Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with TRMPBF suffix. Rev A 2 For more information www.analog.com CAPFLT V SYS BAL SCAP RSTFB SW SYSGD SW CAPFB CAPSEL