LTC4015 Multichemistry Buck Battery Charger Controller with Digital Telemetry System FEATURESDESCRIPTION n Multichemistry Li-Ion/Polymer, LiFePO4, or Lead- The LTC®4015 is a complete synchronous buck controller/ Acid Battery Charger with Termination charger with pin-selectable, chemistry specific charging n High Efficiency Synchronous Buck Battery Charger and termination algorithms. n Digital Telemetry System Monitors VBAT, IBAT, The LTC4015 can charge Li-Ion/Polymer, LiFePO R 4, or lead- BAT,NTC Ratio (Battery Temperature), VIN, IIN, acid batteries. Battery charge voltage is pin selectable and VSYSTEM, Die Temperature I2C 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 be individually adjusted via the I2C 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 ported for lithium chemistry batteries. The LTC4015 also n Optional I2C Serial Port Control includes automatic recharge, precharge (Li-Ion) and NTC n Input Current Limit Prioritizes System Load Output thermistor protection. The LTC4015's I2C port allows user n Input and Output Ideal Diodes Provide Low Loss PowerPath™ Operation customization of charger algorithms, reading of charger status information, configuration of the maskable and n Instant-On Operation with Discharged Battery programmable alerts, plus use and configuration of the APPLICATIONS Coulomb counter. n Portable Medical Instruments/Military Equipment Available in a 38-Lead 5mm × 7mm QFN package. L n , LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and 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 APPLICATION12VIN 2-Cell Li-Ion 8A Step-Down Battery Charger ControllerStep-Down Charger Efficiency and R V SNSI IN Coulomb Counter Error vs 12V SYS Battery Charge Current 100 0.5 95 INFET CLP CLN SYS SYSM5 COULOMB COUNTER ERROR (%) VIN OUTFET 90 0.0 UVCLFB INTVCC 85 SMBALERT DRVCC 80 –0.5 DV BOOST µCONTROLLER CC 75 SCL TG SDA 70 –1.0 EFFICIENCY (%) CELLS0 LTC4015 65 SW INTVCC CELLS1 60 EFFICIENCY –1.5 QC ERROR CELLS2 BG 55 CHEM0 50 –2.0 CHEM1 CSPM5 0.1 1 10 RT CSP CHARGE CURRENT (A) 4015 TA01b V R C SNSB CSN CCREFP BATSENS NTCBIAS CCREFM 2-CELL Li-Ion LEAD-ACID RNTCBIAS BATTERY EQUALIZE EQ (PADDLE) SGND GND MPPT 2P5V NTC PACK CHARGE CC T RNTC 4015 TA01a 4015fb For more information www.linear.com/LTC4015 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Data Sheet Conventions Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram I2C Timing Diagram Operation Applications Information Register Description DETAILED Register Descriptions Typical Applications Package Description Revision History Typical Application Related Parts