LTC3625/LTC3625-1 1A High Efficiency 2-Cell Supercapacitor Charger with Automatic Cell Balancing Fae Tseru Dpircse Tnoi n High Efficiency Step-Up/Step-Down Charging of Two The LTC 3625/LTC3625-1 are programmable supercapaci- Series Supercapacitors tor chargers designed to charge two supercapacitors in n Automatic Cell Balancing Prevents Capacitor series to a fixed output voltage (4.8V/5.3V or 4V/4.5V Overvoltage During Charging selectable) from a 2.7V to 5.5V input supply. Automatic n Programmable Charging Current Up to 500mA cell balancing prevents overvoltage damage to either (Single Inductor), 1A (Dual Inductor) supercapacitor while maximizing charge rate. No balancing n V = 2.7V to 5.5V resistors are required. IN n Selectable 2.4V/2.65V Regulation per Cell (LTC3625) High efficiency, high charging current, low quiescent cur- n Selectable 2V/2.25V Regulation per Cell (LTC3625-1) rent and low minimum external parts count (one inductor, n Low No-Load Quiescent Current: 23A one bypass capacitor at V and one programming resistor) IN n I , I < 1A in Shutdown VOUT VIN make the LTC3625/LTC3625-1 ideally suited for small form n Low Profile 12-lead 3mm 4mm DFN Package factor backup or high peak power systems. a acilpp Tsnoi Charging current/maximum input current level is pro- grammed with an external resistor. When the input supply is n Servers, RAID Systems, Mass Storage, High Current removed and/or the EN pin is low, the LTC3625/LTC3625-1 Backup Supplies automatically enter a low current state, drawing less than n Solid State Hard Drives 1A from the supercapacitors. n Wireless Power Meters n High Peak Power Boosted Supplies The LTC3625/LTC3625-1 are available in a compact 12-lead 3mm 4mm 0.75mm DFN package. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. T lacipy a acilpp Tn oi 1A SCAP Charger Charging Two 2:1 Mismatched Supercapacitors 6 LTC3625 V V C = 50F IN OUT TOP V V IN OUT C = 100F BOT 2.7V TO 5.5V 4.8V 5 10F R = 61.9k PROG 3.3H SW2 CTL = 0 C 0.1F TOP V = 0 SEL 3.3H 4 SW1 V V OUT MID PROG C 0.1F BOT 3 61.9k V MID 2 PFI PGOOD EN PFO CTL 1 V SEL 3625 TA01a 0 0 20 40 60 80 100 120 140 160 180 200 TIME (SECONDS) 3625 TA01b 3625f VOLTAGE (V)LTC3625/LTC3625-1 a ulosb T e Mixa Mu M r a Tsgni p ni c no Farugi Tnoi (Note 1) TOP VIEW V , V (Transient) t < 1ms, IN OUT Duty Cycle < 1% .......................................... 0.3V to 7V SW1 1 12 SW2 V , V , V , PGOOD, IN OUT MID V 2 11 V IN OUT CTL, PROG, PFI, PFO ................................... 0.3V to 6V CTL 3 10 V MID 13 GND EN, V ........................................... 0.3V to V + 0.3V V 4 9 PGOOD SEL IN SEL V Short-Circuit Duration ............................. Indenfi ite EN 5 8 PFO OUT I , I ............................................................50mA PROG 6 7 PFI PGOOD PFO I ........................................................................1mA PROG DE PACKAGE I , I , I , I (Note 2) ...................................3A 12-LEAD (4mm s 3mm) PLASTIC DFN VIN SW1 SW2 VOUT T = 125C, = 43C/W JMAX JA Operating Junction Temperature Range EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB (Notes 3, 4) ............................................ 40C to 125C Storage Temperature Range .................. 65C to 125C o r D re i n Fro Ma Tnoi LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3625EDE PBF LTC3625EDE TRPBF 3625 12-Lead (4mm 3mm) Plastic DFN 40C to 125C LTC3625EDE-1 PBF LTC3625EDE-1 TRPBF 36251 12-Lead (4mm 3mm) Plastic DFN 40C to 125C LTC3625IDE PBF LTC3625IDE TRPBF 3625 12-Lead (4mm 3mm) Plastic DFN 40C to 125C LTC3625IDE-1 PBF LTC3625IDE-1 TRPBF 36251 12-Lead (4mm 3mm) Plastic DFN 40C to 125C Consult LTC Marketing for parts speciefi d with wider operating temperature ranges. *The temperature grade is identiefi d by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: