POWER LOSS (W) LT3651-4.1/LT3651-4.2 Monolithic 4A Wide Input 1 Cell Li-Ion Battery Charger FEATURES DESCRIPTION n Wide Input Voltage Range: Up to 32V The LT 3651 is a 1 cell 4A Li-Ion/Polymer battery charger (40V Absolute Maximum) that operates with input voltages up to 32V. An efficient n Programmable Charge Current Up to 4A monolithic average current mode synchronous switching n Selectable C/10 or Onboard Timer Termination regulator provides constant current, constant voltage n Dynamic Charge Rate Programming/Soft-Start charging with programmable maximum charge current. n Programmable Input Current Limit A charging cycle starts with battery insertion or when n 0.5% Float Voltage Accuracy the battery voltage drops 2.5% below the float voltage. n 7.5% Charge Current Accuracy Charger termination is selectable as either charge current n 4% C/10 Detection Accuracy or internal safety timer timeout. Charge current termina- n NTC Resistor Temperature Monitor tion occurs when the charge current falls to one-tenth n Auto-Recharge at 97.5% Float Voltage the programmed maximum current (C/10). Timer based n Auto-Precondition <70% Float Voltage termination is typically set to three hours and is user pro- n Bad Battery Detection with Auto-Reset grammable (charging continues below C/10 until timeout). n Average Current Mode, Synchronous Switcher Once charging is terminated, the LT3651 supply current n User Programmable Frequency drops to 85A into a standby mode. n Low Profile (0.75mm) 5mm 6mm 36-Pin The LT3651 offers several safety features. A discharged QFN Package battery is preconditioned with a small trickle charge and generates a signal if unresponsive. A thermistor monitors APPLICATIONS battery temperature, halting charging if out of range. Ex- n Industrial Handheld Instruments cessive die temperature reduces charge current. Charge n 12V to 24V Automotive and Heavy Equipment current is also reduced to maintain constant input current n Desktop Cradle Chargers to prevent excessive input loading. n Notebook Computers The LT3651 is available in a 5mm 6mm 36-pin QFN L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and package. PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION Efficiency, Power Loss vs DC IN 6.5V to 32V Single Cell 4A Charger 86 4.4 V = 3.9 TO BAT DC E FF IN SYSTEM 85 4.0 6.5V TO 32V LOAD 22F 100k 10V CLP CLN V Si7611DN IN 84 3.6 SHDN SW 100k ACPR 1F FAULT 6.5H 83 3.2 BOOST CHRG WRTH 744314650 1N5819 LT3651-4.2 SENSE 82 2.8 RT 24m 301k 81 2.4 P LOSS TIMER BAT + NTC 100F BATTERY 80 2.0 I RNG/SS GND LIM 365142 TA01a 5 10 15 20 25 30 365142 TA01b DC (V) IN 365142ff 1 For more information www.linear.com/LT3651-4.1 EFFICIENCY (%)LT3651-4.1/LT3651-4.2 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V .......................................................................... 40V IN CLN, CLP, SHDN, CHRG, FAULT, ACPR ............................... V + 0.5V Up to 40V IN 36 35 34 33 32 31 30 29 CLP CLN .............................................................0.5V NTC 1 28 I LIM ACPR 2 27 SHDN SW ...........................................................................40V BAT 3 26 CHRG SW V ..................................................................4.5V IN 37 SENSE 4 25 FAULT BOOST ......................................... SW + 10V Up to 50V BOOST 5 24 TIMER SENSE, BAT ............................................................ 10V GND 6 23 GND SENSE-BAT ............................................. 0.5V to 0.5V SW 7 22 SW NC 8 21 NC 38 TIMER, RNG/SS, I , NTC, RT .............................. 2.5V LIM NC 9 20 NC Operating Junction Temperature Range NC 10 19 NC (Notes 2, 3) ................................................40 to 125C 11 12 13 14 15 16 17 18 Storage Temperature Range .......................65 to 150C UHE PACKAGE 36-LEAD (5mm 6mm) PLASTIC QFN T = 125C, = 43C/W JMAX JA EXPOSED PAD (PIN 37) IS GND, MUST BE SOLDERED TO PCB EXPOSED PAD (PIN 38) IS SW, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3651EUHE-4.1 PBF LT3651EUHE-4.1 TRPBF 365141 40C to 125C 36-Lead (5mm 6mm) Plastic QFN LT3651IUHE-4.1 PBF LT3651IUHE-4.1 TRPBF 365141 36-Lead (5mm 6mm) Plastic QFN 40C to 125C LT3651EUHE-4.2 PBF LT3651EUHE-4.2 TRPBF 365142 36-Lead (5mm 6mm) Plastic QFN 40C to 125C LT3651IUHE-4.2 PBF LT3651IUHE-4.2 TRPBF 365142 36-Lead (5mm 6mm) Plastic QFN 40C to 125C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: