LTC3351 Hot Swappable Supercapacitor Charger, Backup Controller and System Monitor FEATURES DESCRIPTION n Integrated Hot Swap Controller with Circuit Breaker The LTC 3351 is a backup power controller that charges n High Efficiency Synchronous Step-Down CC/CV and monitors a series stack of one to four supercapaci- Charging of One to Four Series Supercapacitors tors. The LTC3351s synchronous step-down controller n Step-Up Mode in Backup Provides Greater drives N-channel MOSFETs for constant current/constant Utilization of Stored Energy in Supercapacitors voltage charging with programmable input current limit. n 16-Bit ADC for Monitoring System Voltages/ In addition, the step-down converter runs in reverse as Currents, Capacitance and ESR a step-up converter to deliver power from the superca- n Programmable Undervoltage and Overvoltage pacitor stack to the backup supply rail. Internal balancers Thresholds to 35V eliminate the need for external balance resistors and each n V : 4.5V to 35V, V : Up to 5V per Capacitor, capacitor has a shunt regulator for overvoltage protection. IN CAP(n) Charge/Backup Current: >10A The LTC3351 monitors system voltages, currents, stack n Programmable Input Current Limit Prioritizes System 2 capacitance and ESR which can all be read over the I C/ Load Over Capacitor Charge Current SMBus port. The hot swap controller uses N-channel n All N-FET Charger Controller and PowerPath Controller MOSFETs for inrush control and a low loss path from n Compact 44-Lead 4mm 7mm QFN Package the input to the output. The ideal diode controller uses an N-channel MOSFET for a low loss power path from APPLICATIONS the supercapacitors to the output. The LTC3351 is avail- n able in a thermally enhanced low profile 44-lead 4mm Swappable PCIE Cards with NVM n 7mm0.75mm QFN surface mount package. High Current 12V Ride-Through UPS All registered trademarks and trademarks are the property of their respective owners. Patents n Servers/Mass Storage/High Availability Systems pending. TYPICAL APPLICATION I (STEP-DOWN) I CHG BACKUP V V IN OUT Example Hot Swap from 12V HS GATE ISNSP HS/ ISNSM V IN ISNSP CHG UV OUTFB 2V/DIV V > V CAP OUT OV (DIRECT OUTFET CONNECT) V < V V CAP OUT OUT (STEP-UP) 2V/DIV TGATE SW I BGATE IN LTC3351 0.2A/DIV ICAP 5ms/DIV VCAP 2 I C CAP4 V CAP 3351 TA01 10F CAP3 10F CAP2 10F CAP1 10F CAPRTN 3351 TA01a CAPFB Rev. B 1 Document Feedback For more information www.analog.comLTC3351 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V , V , ISNSP HS, ISNSP CHG, ISNSM, IN OUT UV, OV, RETRYB, OUTFB ....................... 0.3V to 40V VCAP .......................................................... 0.3V to 22V 44 43 42 41 40 39 38 CAP4-CAP3, CAP3-CAP2, CAP SLCT0 1 37 ISNS HS CAP2-CAP1, CAP1-CAPRTN ................. 0.3V to 5.5V CAP SLCT1 2 36 ISNSP CHG DRV , CAPFB, SMBALERT, CAPGD, VINGD 3 35 ISNSM CC VINGD, GPI, SDA, SCL ...........0.3V to INTV + 0.3V SCL 4 34 RETRYB CC SDA 5 V 33 BST ......................................................... 0.3V to 45.5V OUT SMBALERT 6 32 INTV CC CAP SLCT0, CAP SLCT1 ......... 0.3V to VCC2P5 + 0.3V CAPGD 7 DRV 31 CC BST to SW ................................................ 0.3V to 5.5V 45 VC 8 30 BGATE PGND ISNSP HS to ISNSM, CAPFB BST 9 29 ISNSP CHG to ISNSM, ICAP to VCAP ... 0.3V to 0.3V OUTFB 10 28 TGATE I .................................................................100mA INTVCC SGND SW 11 27 I , I ............................................ 600mA CAP(1,2,3,4) CAPRTN RT 12 26 VCC2P5 I , I , I ......................................10mA GPI ICAP 13 25 CAPGD VINGD SMBALERT ITST 14 24 V Operating Junction Temperature Range CAP CAPRTN OUTFET 15 23 (Notes 2, 3) ........................................ 40C to 125C 16 17 18 19 20 21 22 Storage Temperature Range .................. 65C to 150C UFF PACKAGE 44-LEAD (4mm 7mm) PLASTIC QFN T = 125C, = 36.4C/W, = 2.6C/W JMAX JA JC EXPOSED PAD (PIN 45) IS PGND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3351EUFF PBF LTC3351EUFF TRPBF 3351 44-Lead (4mm 7mm) Plastic QFN 40C to 125C LTC3351IUFF PBF LTC3351IUFF TRPBF 3351 44-Lead (4mm 7mm) Plastic QFN 40C to 125C Contact the factory for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with TRMPBF suffix. Rev. B 2 For more information www.analog.com CAP1 CTIMER CAP2 OV CAP3 UV CAP4 V IN CFP HS GATE CFN SRC VCAPP5 CSS