LTC4020 55V Buck-Boost Multi-Chemistry Battery Charger FeaTuresDescripTion n Wide Voltage Range: 4.5V to 55V Input, Up to 55V The LTC®4020 is a high voltage power manager provid- Output (60V Absolute Maximums) ing PowerPath™ instant-on operation and high efficiency n Synchronous Buck-Boost DC/DC Controller battery charging over a wide voltage range. An onboard n Li-Ion and Lead-Acid Charge Algorithms buck-boost DC/DC controller operates with battery and/or n ±0.5% Float Voltage Accuracy system voltages above, below, or equal to the input voltage. n ±5% Charge Current Accuracy The LTC4020 seamlessly manages power distribution n Instant-On for Heavily Discharged Batteries between battery and converter outputs in response to load n Ideal Diode Controller Provides Low Loss variations, battery charge requirements and input power PowerPath When Input Power is Limited supply limitations. n Input Voltage Regulation for High Impedance InputSupplies and Solar Panel Peak Power Operation The LTC4020 battery charger can provide a constant-current/ n Onboard Timer for Protection and Termination constant-voltage charge algorithm (CC/CV), constant- n Bad Battery Detection with Auto-Reset current charging (CC), or charging with an optimized 4-step, n NTC Input for Temperature Qualified Charging 3-stage lead-acid battery charge profile. Maximum converter n Binary Coded Open-Collector Status Pins and battery charge currents are resistor programmable. n Low Profile (0.75mm) 38-Pin 5mm × 7mm QFN The IC's instant-on operation ensures system load power Package even with a fully discharged battery. Additional safety features include preconditioning for heavily discharged applicaTions batteries and an integrated timer for termination and n Portable Industrial and Medical Equipment protection. n Solar-Powered Systems L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and n PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the Military Communications Equipment property of their respective owners. Protected by U.S. Patents, including 7583113 and 8405362. n 12V to 24V Embedded Automotive Systems Typical applicaTion5V to 30V 6-Cell Lead-Acid Supply/ChargerBuck-Boost DC/DC Converter Controller with PowerPath Battery Charger AcceptsMaximum Power Efficiency vs VInputs from 4.5V to 55V and Produces Output Voltages Up to 55VIN(Application Circuit on Page 37) BUCK-BOOST RSENSEA DC/DC CONVERTER PowerPath BATTERY CHARGER 100 100 V V IN VOUT OUT = 14V 90 EFFICIENCY TG2 CSP 95 80 LTC4020 RCS 70 POWER (W) CSN 90 60 BG2 INPUT POWER BGATE 50 VFB 85 40 RSENSEB EFFICIENCY (%) 30 SENSGND 80 20 SENSBOT NTC P(LOSS) 10 BG1 75 0 RNTC 5 10 15 20 25 30 TG1 VIN (V) 4020 TA01b SENSTOP SENSVIN VFBMAX 4020 TA01a 4020fd For more information www.linear.com/LTC4020 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Electrical Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Application Related Parts