Datasheet LTC4007-1 (Analog Devices)

LTC4007-1 4A, High Efficiency, Li-Ion Battery Charger
FeaTures DescripTion
n
Charger Controller for 3- or 4-Cell
The LTC®4007-1 is a constant-current/constant-voltage
Lithium-Ion Batteries
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 n
±0.8% Charging Voltage Accuracy
generate audible noise even when using ceramic capaci- n
Built-In Charge Termination for Li-Ion Batteries
tors. Charging current is programmable to ±4% accuracy n
AC Adapter Current Limiting Maximizes Charge Rate*
using a programming resistor. Charging current can also be n Thermistor Input for Temperature Qualified Charging monitored 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, pro- n Programmable Charge Current: ±4% Accuracy grammed by an external resistor, sets the total charge time. n Indicator Outputs for Charging, C/10 Current Detection, AC Adapter Present, Low Battery, Input The LTC4007-1 includes a thermistor input, which Current Limiting and Faults suspends charging if an unsafe temperature condition n Charging Current Monitor Output is detected. If the cell voltage is less than 3.25V, a low- n Available in a 24-Pin 4mm × 5mm QFN Package battery indicator asserts and can be used to program a trickle charge current to safely charge depleted batteries.
applicaTions
The FAULT pin is also asserted and charging terminates if the low-battery condition persists for more than 1/4 of n Notebook Computers the total charge time. n Portable Instruments L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and n Battery-Backup Systems No RSENSE is a trademark of Linear Technology Corporation. All other trademarks are the n property of their respective owners. Li-Ion Chargers Protected by U.S. Patents including 5723970.
Typical applicaTion 12.6V, 4A Li-Ion Battery Charger
INPUT SWITCH DCIN 0V TO 28V 0.1µF
LOW BATTERY AUTO THRESHOLD (Per Cell)
4.99k
PART RESTART (4.2V/4.1V)
V 3C4C DCIN LOGIC LTC4007-1 NO 3.25V/3.173V 100k 100k 100k CHEM INFET 15nF 0.025Ω LTC4007 YES 2.5V/2.44V LOBAT LOBAT CLP SYSTEM LOAD ICL ICL LTC4007-1 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: Si4431BDY NTC Q2: FDC645N 309k TIMING RESISTOR 26.7k (~2 HOURS) 0.12µF 40071 TA01 40071fa For more information www.linear.com/LTC4007-1 1 Document Outline Description Typical Application Absolute Maximum Ratings Typical Performance Characteristics Pin Functions Block Diagram Operation Typical Application Related Parts