LTC4098-3.6 USB Compatible Switching Power Manager/LiFePO Charger 4 with Overvoltage Protection FEATURES DESCRIPTION TM n Switching Regulator with Bat-Track Adaptive The LTC 4098-3.6 is a high efficiency USB PowerPath Output Control Makes Optimal Use of Limited controller and full-featured LiFePO battery charger. It seam- 4 Power Available from USB Port to Charge Battery lessly manages power distribution from multiple sources and Power Application including USB, wall adapter, automotive, Firewire or other n Charge Control Algorithm Specifically Designed high voltage DC/DC converters, and a LiFePO battery. 4 for LiFePO (Lithium Iron Phosphate) 4 The LTC4098-3.6 charge algorithm is optimized for LiFePO 4 n Overvoltage Protection Guards Against Damage by implementing a 1-hour float voltage termination timer n Bat-Track External Step-Down Switching Regulator and a 0C to 60C NTC-based charge qualification range. Control Maximizes Efficiency from Automotive, Furthermore, completely discharged batteries are charged Firewire and Other High Voltage Input Sources at the full programmed charge current. n 180m Internal Ideal Diode Plus External Ideal Diode TM The LTC4098-3.6s switching regulator can automatically Controller Seamlessly Provide Low Loss PowerPath limit its input current for USB compatibility. For automo- When Input Power Is Limited or Unavailable n tive and other high voltage applications, the LTC4098-3.6 Preset 3.6V Charge Voltage with 0.5% Accuracy n interfaces with an external switching regulator. Both the Instant-On Operation with Discharged Battery n USB input and the auxiliary input controller feature Bat- 700mA Maximum Load Current from USB Port n Track optimized charging to provide maximum power to 2A Maximum Input Current from Internal Switching the application and reduced heat in high power density ap- Regulator n plications with input supplies from 5V to as high as 38V. 1.5A Maximum Charge Current with Thermal Limiting n 20-Lead 3mm 4mm 0.75mm QFN Package An overvoltage protection circuit guards the LTC4098-3.6 from high voltage damage on the VBUS pin with just two APPLICATIONS external components. n High Peak Power Battery-Powered Equipment The LTC4098-3.6 is available in a 20-lead 3mm 4mm n Backup Applications 0.75mm QFN surface mount package. n High Reliability Handhelds L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Bat Track and PowerPath are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Reduced Power Dissipation TYPICAL APPLICATION vs Linear Battery Charger 3.0 High Efficiency USB Compatible LiFePO Battery Charger with Overvoltage Protection 4 V = 5V IN PROG = 500 LINEAR BATTERY 3.3H I = 1.1A 2.5 SYSTEM CHRG CHARGER 5V/USB V SW BUS 10x MODE LOAD 10F 2.0 LTC4098-3.6 OVGATE V OUT ADDITIONAL POWER 6.04k 1.5 AVAILABLE FOR CHARGING OVSENS 3 D0-D2 TO C BAT 1.0 CLPROG PROG GND BATSENS 10F SWITCHING BATTERY 0.5 CHARGER + 0.1F 3.01k 500 LiFePO 4 0 409836 TA01a 2.70 2.85 3.00 3.15 3.30 3.45 3.60 BATTERY VOLTAGE (V) 409836 TA01b 409836f 1 POWER DISSIPATION (W)LTC4098-3.6 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Notes 1, 3) V , WALL (Transient) t < 1ms, BUS TOP VIEW Duty Cycle < 1% .......................................... 0.3V to 7V V , WALL (Static), BAT, BATSENS, BUS 20 19 18 17 CHRG, NTC, ................................................. 0.3V to 6V OVSENS 1 16 D1 D0, D1, D2 .........0.3V to Max (V , V , BAT) + 0.3V OVGATE 2 15 D0 BUS OUT CLPROG 3 21 14 SW I .................................................................10mA OVSENS GND NTCBIAS 4 13 V BUS I ....................................................................3mA CLPROG NTC 5 12 V OUT I ........................................................................2mA PROG BATSENS 6 11 BAT I ......................................................................50mA CHRG 7 8 9 10 I , I , I .......................................................2.25A VOUT SW BAT I ......................................................................5mA ACPR UDC PACKAGE Operating Temperature Range.................. 40C to 85C 20-LEAD (3mm 4mm) PLASTIC QFN Junction Temperature ........................................... 125C T = 125C, = 43C/W JMAX JA EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB Storage Temperature Range ................... 65C to 125C ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC4098EUDC-3.6 PBF LTC4098EUDC-3.6 TRPBF LFYR 40C to 85C 20-Lead (3mm 4mm) Plastic QFN Consult LTC Marketing for parts specified with wider operating temperature ranges. For more information on lead free part marking, go to: