BATTERY VOLTAGE(V) LTC1731-8.2/LTC1731-8.4 Lithium-Ion Linear Battery Charger Controller FEATURES DESCRIPTIO n Complete Linear Charger Controller for The LTC 1731-8.2/LTC1731-8.4 are complete constant- 2-Cell Lithium-Ion Batteries current/constant-voltage linear charger controllers for 2- n 1% Voltage Accuracy cell lithium-ion (Li-Ion)batteries. Nickel-cadmium (NiCd) n Programmable Charge Current and nickel-metal-hydride (NiMH) batteries can also be n C/10 Charge Current Detection Output charged with constant current using external termina- n Programmable Charge Termination Timer tion. The external sense resistor sets the charge current n Space Saving 8-Pin MSOP Package with 7% accuracy. An internal resistor divider and preci- n Automatic Sleep Mode When Input Supply sion reference set the final float potential with 1% accu- is Removed (15m A Battery Drain) racy. The output float voltages are set internally to 8.2V n Automatic Trickle Charging of Low Voltage Cells (LTC1731-8.2) or 8.4V (LTC1731-8.4). n Programmable for Constant-Current-Only Mode When the input supply is removed, the LTC1731-8.2/ LTC1731-8.4 automatically enter a low current sleep mode, U dropping the battery drain current to typically 15m A. An APPLICATIO S internal comparator detects the end-of-charge (C/10) con- n Cellular Phones dition while a programmable timer, using an external n Handheld Computers capacitor, sets the total charge time. Fully discharged cells n Charging Docks and Cradles are automatically trickle charged at 10% of the pro- n Programmable Current Source grammed current until battery voltage exceeds 4.95V. The LTC1731-8.2/LTC1731-8.4 are available in the 8-pin MSOP and SO packages. For 1-cell Li-Ion battery charg- , LTC and LT are registered trademarks of Linear Technology Corporation. ing, see the LTC1731-4.1 and LTC1731-4.2 data sheets. TYPICAL APPLICATIO 400mA Li-Ion Charger Typical Li-Ion Charge Cycle V = 9V IN 9 CONSTANT CONSTANT MBRM120T3 CURRENT VOLTAGE 7 BATTERY VOLTAGE R 2k SENSE V 1F CC 400 8 0.2 8 400mA HR BATTERY CHARGE SENSE STATUS 2 6 Q1 300 CHRG DRV Si9430DY CHARGE CURRENT LTC1731-8.4 I = 400mA BAT 3 1 200 7 TIMER BAT CHRG 5 LED OFF TIMER PROG 100 C TIMER STOPS 0.1F GND + R * 2-CELL PROG 10F 4 19.6k Li-ION 0 6 2.0 3.0 0 0.5 1.0 1.5 2.5 1731 TA01 TIME (HOURS) *SHUTDOWN INVOKED BY FLOATING THE PROG PIN 1731 TA01b sn1731 17318fs 1 CHARGE CURRENT (mA) U ULTC1731-8.2/LTC1731-8.4 ABSOLUTE MAXIMUM RATINGS (Note 1) Input Supply Voltage (V ) ................................... 13.2V Operating Temperature Range (Note 2) .....40 to 85 C CC SENSE, DRV, BAT, TIMER, PROG ............ 0.3V to V Storage Temperature Range ................. 65 C to 150 C CC Lead Temperature (Soldering, 10 sec).................. 300 C CHRG..................................................... 0.3V to 13.2V PACKAGE/ORDER INFORMATION ORDER PART ORDER PART TOP VIEW NUMBER NUMBER TOP VIEW BAT 1 8 SENSE BAT 1 8 SENSE LTC1731EMS8-8.2 LTC1731ES8-8.2 CHRG 2 7 V CHRG 2 7 V CC CC TIMER 3 6 DRV LTC1731EMS8-8.4 LTC1731ES8-8.4 TIMER 3 6 DRV GND 4 5 PROG GND PROG 4 5 MS8 PACKAGE MS8 PART MARKING S8 PART MARKING 8-LEAD PLASTIC MSOP S8 PACKAGE T = 150 C, q = 200 C/W 8-LEAD PLASTIC SO JMAX JA LTSW 173182 T = 150 C, q = 125 C/W JMAX JA LTPE 173184 Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 C. V = 9V unless otherwise noted. A CC SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Input Supply Voltage l 8.8 12 V CC I Input Supply Current Charger On, Current Mode l 13 mA CC Shutdown Mode l 12 mA Sleep Mode (Battery Drain Current) 15 30 m A V Regulated Output Voltage LTC1731-8.2 (9V V 12V) l 8.118 8.2 8.282 V BAT CC LTC1731-8.4 (9V V 12V) l 8.316 8.4 8.484 V CC I Current Mode Charge Current R = 19.6k, R = 0.2W 465 500 535 mA BAT PROG SENSE R = 19.6k, R = 0.2W l 415 500 585 mA PROG SENSE = 97.6k, R = 0.2W 70 100 130 mA R PROG SENSE I Trickle Charge Current V = 4V, R = 19.6k, I = (V V )/0.2W l 30 50 100 mA TRIKL BAT PROG TRIKL CC SENSE V Trickle Charge Threshold Voltage BAT Rising l 4.7 4.95 5.1 V TRIKL V V Undervoltage Lockout Voltage V Rising l 8.2 8.8 V UV CC CC D V V Undervoltage Lockout Hysteresis V Falling 200 mV UV CC CC V Manual Shutdown Threshold Voltage PROG Pin Rising 2.457 V MSD PROG Pin Falling 2.446 V I Drive Pin Current V = V 2V 26 m A DRV DRV CC sn1731 17318fs 2 U W U U WWW