COULOMB COUNTER ERROR (%) LTC4015 Multichemistry Buck Battery Charger Controller with Digital Telemetry System FEATURES DESCRIPTION n Multichemistry Li-Ion/Polymer, LiFePO , or Lead- The LTC 4015 is a complete synchronous buck controller/ 4 Acid Battery Charger with Termination charger with pin-selectable, chemistry specific charging n and termination algorithms. High Efficiency Synchronous Buck Battery Charger n Digital Telemetry System Monitors V , I , BAT BAT The LTC4015 can charge Li-Ion/Polymer, LiFePO , or lead- 4 R ,NTC Ratio (Battery Temperature), V , I , BAT IN IN acid batteries. Battery charge voltage is pin selectable and V , Die Temperature 2 SYSTEM I C adjustable. Input current limit and charge current can n Coulomb Counter and Integrated 14-Bit ADC be accurately programmed with sense resistors and can n Wide Charging Input Voltage Range: 4.5V to 35V 2 be individually adjusted via the I C serial port. A digital n Wide Battery Voltage Range: Up to 35V telemetry system monitors all system power parameters. n Input Undervoltage Charge Current Limit Loop Safety timer and current termination algorithms are sup- n Maximum Power Point Tracking 2 ported for lithium chemistry batteries. The LTC4015 also n Optional I C Serial Port Control includes automatic recharge, precharge (Li-Ion) and NTC n Input Current Limit Prioritizes System Load Output 2 thermistor protection. The LTC4015 s I C port allows user n Input and Output Ideal Diodes Provide Low Loss customization of charger algorithms, reading of charger PowerPath Operation status information, configuration of the maskable and n Instant-On Operation with Discharged Battery programmable alerts, plus use and configuration of the Coulomb counter. APPLICATIONS Available in a 38-Lead 5mm 7mm QFN package. n Portable Medical Instruments/Military Equipment L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and n Industrial Handhelds/Lighting PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the n property of their respective owners. Ruggedized Notebook/Tablet Computers TYPICAL APPLICATION 12V 2-Cell Li-Ion 8A Step-Down Battery Charger Controller IN Step-Down Charger Efficiency and R SNSI Coulomb Counter Error vs SYS Battery Charge Current 100 0.5 95 INFET CLP CLN SYS SYSM5 V OUTFET IN 90 0.0 INTV CC UVCLFB 85 DRV CC SMBALERT 80 0.5 BOOST DV CC CONTROLLER 75 SCL TG SDA 70 1.0 CELLS0 LTC4015 65 SW EFFICIENCY CELLS1 INTV CC 60 1.5 QC ERROR CELLS2 BG 55 CHEM0 50 2.0 CSPM5 CHEM1 0.1 1 10 RT CSP CHARGE CURRENT (A) 4015 TA01b R SNSB V C CSN CCREFP BATSENS NTCBIAS CCREFM R NTCBIAS (PADDLE) EQ NTC SGND GND MPPT 2P5V CC 4015 TA01a 4015fb 1 For more information www.linear.com/LTC4015 V IN 12V 2-CELL Li-Ion LEAD-ACID BATTERY EQUALIZE PACK CHARGE T R NTC EFFICIENCY (%)LTC4015 TABLE OF CONTENTS Features ............................................................................................................................ 1 Applications ....................................................................................................................... 1 Typical Application ............................................................................................................... 1 Description......................................................................................................................... 1 Absolute Maximum Ratings ..................................................................................................... 3 Order Information ................................................................................................................. 3 Data Sheet Conventions ......................................................................................................... 3 Pin Configuration ................................................................................................................. 3 Electrical Characteristics ........................................................................................................ 4 Typical Performance Characteristics .........................................................................................10 Pin Functions .....................................................................................................................13 Block Diagram ....................................................................................................................15 2 I C Timing Diagram .............................................................................................................16 Operation..........................................................................................................................17 Applications Information .......................................................................................................42 Register Description ............................................................................................................49 DETAILED Register Descriptions ..............................................................................................55 Typical Applications .............................................................................................................72 Package Description ............................................................................................................74 Revision History .................................................................................................................75 Typical Application ..............................................................................................................76 Related Parts .....................................................................................................................76 4015fb 2 For more information www.linear.com/LTC4015