LTC4007 4A, High Efficiency, Standalone Li-Ion Battery Charger FEATURESDESCRIPTION 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 APPLICATION12.6V, 4A Li-Ion Battery Charger INPUT SWITCH DCIN 0V TO 28V 0.1µF 4.99k V 3C4C DCIN LOGIC 100k 100k 100k CHEM INFET 15nF 0.025Ω LOBAT LOBAT CLP SYSTEM I LOAD CL ICL LTC4007 CLN 20µF ACP ACP TGATE Q1 10µH 0.025Ω SHDN SHDN BGATE Li-Ion FAULT FAULT PGND Q2 20µF BATTERY CHG CHG CSP FLAG FLAG BAT 3.01k 32.4k NTC PROG 3.01k CHARGING RT ITH CURRENT THERMISTOR MONITOR 0.47µF GND 0.0047µF 10k 6.04k Q1: Si4431DY NTC Q2: FDC6459 309k TIMING RESISTOR 26.7k (~2 HOURS) 0.12µF 4007 TA01 Rev D Document Feedback For more information www.analog.com 1 Document Outline Description Typical Application Absolute Maximum Ratings Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Test Circuit Operation Applications Information Package Description Revision History Typical Application Related Parts
