LTC4007 4A, High Efficiency, Standalone Li-Ion Battery Charger FEATURES DESCRIPTION n Complete Charger Controller for 3- or 4-Cell The LTC 4007 is a complete constant-current/constant-volt- Lithium-Ion Batteries age charger controller for 3- or 4-cell lithium-ion batteries. n High Conversion Efficiency: Up to 96% The PWM controller uses a synchronous, quasi-constant n Output Currents Exceeding 4A frequency, constant off-time architecture that will not gen- n 0.8% Charging Voltage Accuracy erate audible noise even when using ceramic capacitors. n Built-In Charge Termination for Li-Ion Batteries Charging current is programmable to 4% accuracy using n AC Adapter Current Limiting Maximizes Charge Rate* a programming resistor. Charging current can also be mon- n Thermistor Input for Temperature Qualified Charging itored as a voltage across the programming resistor. n Wide Input Voltage Range: 6V to 28V The output float voltage is pin programmed for cell count n 0.5V Dropout Voltage Maximum Duty Cycle: 98% (3 cells or 4 cells) and chemistry (4.2V/4.1V). A timer, n Programmable Charge Current: 4% Accuracy programmed by an external resistor, sets the charge ter- n Indicator Outputs for Charging, C/10 Current Detection, mination time. Charging is automatically restarted when AC Adapter Present, Low Battery, Input Current cell voltage falls below 3.9V/cell. Limiting and Faults n Charging Current Monitor Output LTC4007 includes a thermistor input, which suspends n Available in a 24-Pin Narrow SSOP Package charging if an unsafe temperature condition is detected. If the cell voltage is less than 2.5V, a low-battery indicator APPLICATIONS asserts and can be used to program a trickle charge current to safely charge depleted batteries. The FAULT pin is also n Notebook Computers asserted and charging terminates if the low-battery con- n Portable Instruments dition persists for more than 1/4 of the total charge time. n Battery-Backup Systems All registered trademarks and trademarks are the property of their respective owners. All other n Standalone Li-Ion Chargers trademarks are the property of their respective owners. Protected by U.S. Patents including 5723970. TYPICAL APPLICATION 12.6V, 4A Li-Ion Battery Charger INPUT SWITCH DCIN 0V TO 28V 0.1F 4.99k 3C4C DCIN V LOGIC 100k 100k 100k CHEM INFET 0.025 15nF LOBAT LOBAT CLP SYSTEM LOAD I I LTC4007 CLN CL CL 20F ACP ACP TGATE Q1 10H 0.025 SHDN SHDN BGATE Li-Ion Q2 FAULT FAULT PGND BATTERY 20F CHG CHG CSP 3.01k FLAG FLAG BAT 32.4k 3.01k NTC PROG CHARGING CURRENT R ITH T MONITOR THERMISTOR 0.0047F 0.47F GND 6.04k 10k Q1: Si4431DY NTC Q2: FDC6459 TIMING RESISTOR 26.7k 309k 0.12F (~2 HOURS) 4007 TA01 Rev D 1 Document Feedback For more information www.analog.comLTC4007 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW Voltage from DCIN, CLP, CLN to GND ......... +32V/0.3V DCIN 1 24 SHDN PGND with Respect to GND .................................. 0.3V 2 INFET CHG 23 CSP, BAT to GND ......................................... +28V/0.3V ACP 3 22 BGATE 4 21 PGND CHEM, 3C4C, R to GND ................................ +7V/0.3V R T T FAULT 5 20 TGATE NTC .............................................................. +10V/0.3V GND 6 19 CLN ACP, SHDN, CHG, FLAG, 7 CLP 3C4C 18 LOBAT 8 17 FLAG FAULT, LOBAT, I ........................................ +32V/0.3V CL 9 16 CHEM NTC CLP to CLN ............................................................0.5V ITH 10 15 BAT Operating Ambient Temperature Range PROG 11 14 CSP 12 I NC 13 (Note 4) ............................................. 40C to 85C CL GN PACKAGE Operating Junction Temperature ........... 40C to 125C 24-LEAD PLASTIC SSOP Storage Temperature Range .................. 65C to 150C T = 125C, = 88C/W JMAX JA Lead Temperature (Soldering, 10 sec) ...................300C ORDER INFORMATION