Datasheet LT3650-8.2, LT3650-8.4 (Analog Devices)

LT3650-8.2/LT3650-8.4 High Voltage 2 Amp Monolithic 2-Cell Li-Ion Battery Charger
FeaTures DescripTion
n
Wide Input Voltage Range: 9V to 32V (40V Absolute
The LT®3650 is a complete monolithic 2-cell Li-Ion/Polymer
Maximum)
battery charger that operates over a 9V to 32V input volt- n
Programmable Charge Current: Up to 2A
age range (11.5V minimum start-up voltage). The LT3650 n
User-Selectable Termination: C/10 or Onboard
provides a constant-current/constant-voltage charge
Termination Timer
characteristic, with maximum charge current externally n
Dynamic Charge Rate Programming/Soft-Start Pin
programmable up to 2A, set using an external current n
Programmable Input Current Limit
sense resistor. A precondition feature trickle-charges a n 1MHz Fixed Frequency low voltage battery, and bad-battery detection provides a n Average Current Mode Control signal and suspends charging if a battery does not respond n 0.5% Float Voltage Accuracy to preconditioning. n 5% Charge Current Accuracy The LT3650 can be configured to terminate charging when n 2.5% C/10 Detection Accuracy charge current falls to C/10, or one-tenth the programmed n NTC Resistor Temperature Monitor maximum current. Once charging is terminated, the LT3650 n Auto-Recharge at 97.5% Float Voltage enters a low current (85µA) standby mode. An auto-restart n Auto-Precondition at <70% Float Voltage feature starts a new charging cycle if the battery voltage n Bad-Battery Detection with Auto-Reset drops 2.5% from the float voltage, or if a new battery is n Binary Coded Open-Collector Status Pins inserted into a charging system. n 3mm × 3mm DFN-12 or MSOP-12 Package The LT3650 contains a user-programmable internal safety
applicaTions
timer (typically set to a three hour full cycle time). The IC can be configured to use this internal timer if a time-based n Industrial Handheld Instruments termination scheme is desired in which charging can con- n 12V to 24V Automotive and Heavy Equipment tinue below C/10 until a desired time is reached. n Desktop Cradle Chargers n Notebook Computers The LT3650 is available in a low profile (0.75mm) 3mm × L, LT, LTC, LTM, Linear Technology, PowerPath and the Linear logo are registered trademarks 3mm 12-pin DFN and 12-pin MSOP packages. of Linear Technology Corporation. All other trademarks are the property of their respective owners.
Typical applicaTion Charge Current, Efficiency and Power Loss vs Time 11.5V to 32V 2-Cell 2A Charger
3.0 95 VIN = 20V EFFICIENCY CMSH3-40MA CMSH3-40MA 2.5 85 VIN V SW POWER IN 11.5V TO 32V EFFICIENCY (%) LOSS 1µF 2.0 75 10µF CHARGE CLP BOOST 10µH CURRENT LT3650-8.2 CMPSH1-4 1.5 65 SHDN SENSE CHRG 1.0 55 0.05Ω BAT FAULT + 0.5 45 NTC 10µF BATTERY CHARGE CURRENT (A), POWER LOSS (W) TIMER RNG/SS 0 35 0.68µF 0 20 40 60 80 100 120 140 160 180 200 365082 TA01a TIME (MINUTES) 365082 TA01b 36508284fd 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts