LTC1325 Microprocessor-Controlled Battery Management System FEATURES DESCRIPTION n Fast Charge Nickel-Cadmium, Nickel-Metal-Hydride, The LTC 1325 provides the core of a flexible, cost-effec- Lithium Ion or Lead-Acid Batteries under P Control tive solution for an integrated battery management sys- n Flexible Current Regulation: tem. The monolithic CMOS chip controls the fast charging Programmable 111kHz PWM Current Regulator of nickel-cadmium, nickel-metal-hydride, lead-acid or with Built-In PFET Driver lithium batteries under microprocessor control. The de- PFET Current Gating for Use with External Current vice features a programmable 111kHz PWM constant Regulator or Current Limited Transformer current source controller with built-in FET driver, 10-bit n Discharge Mode ADC, internal voltage regulator, discharge-before-charge n Measures Battery Voltage, Battery Temperature and controller, programmable battery voltage attenuator and Ambient Temperature with Internal 10-Bit ADC an easy-to-use serial interface. n Battery Voltage, Temperature and Charge Time The chip may operate in one of five modes: power shut- Fault Protection down, idle, discharge, charge or gas gauge. In power n Built-In Voltage Regulator and Programmable shutdown the supply current drops to 30A and in the idle Battery Attenuator mode, an ADC reading may be made without any switching n Easy-to-Use 3- or 4-Wire Serial P Interface noise affecting the accuracy of the measurement. In the n Accurate Gas Gauge Function discharge mode, the battery is discharged by an external n Wide Supply Range: V = 4.5V to 16V DD transistor while the battery is being monitored by the n Can Charge Batteries with Voltages Greater Than V DD LTC1325 for fault conditions. The charge mode is termi- n Can Charge Batteries from Charging Supplies Greater nated by the P while monitoring any combination of Than V DD battery voltage and temperature, ambient temperature n Digital Input Pins Are High Impedance in and charge time. The LTC1325 also monitors the battery Shutdown Mode for fault conditions before and during charging. In the gas U gauge mode the LTC1325 allows the total charge leaving APPLICATIONS the battery to be calculated. n System Integrated Battery Charger , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATION Battery Charger for up to 8 NiCd or NiMH Cells V DD 4.5V TO 16V + P1 C2 IRF9730 10F D1 1N6818 LTC1325 1 MPU 18 R13 R TRK + REG V C DD (e.g. 8051) REG L1 2 17 4.7F 62H D PGATE R5 OUT 3 16 p1.4 D DIS IN 100 4 15 p1.3 CS V BAT 5 14 p1.2 CLK T BAT R DIS C1 6 13 R1 LTF T AMB 0.1F THERM 1 + BAT 7 12 C REG MCV V IN 22F 8 11 N1 THERM 2 R2 HTF SENSE IRFZ34 9 10 GND FILTER R3 C F R 1F SENSE R4 LTC1325 TA01 1 U ULTC1325 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION (Notes 1, 2) TOP VIEW ORDER PART V to GND............................................................. 17V NUMBER DD REG 1 18 V DD All Other Pins................................ 0.3V to V + 0.3V DD D 2 17 PGATE OUT Operating Temperature Range ..................... 0C to 70C D 3 16 DIS LTC1325CN IN Storage Temperature Range ................. 65C to 150C CS 4 15 V LTC1325CSW BAT Lead Temperature (Soldering, 10 sec).................. 300C CLK 5 14 T BAT LTF 6 13 T AMB MCV 7 12 V IN HTF 8 11 SENSE GND 9 10 FILTER N PACKAGE SW PACKAGE 18-LEAD PDIP 18-LEAD PLASTIC SO WIDE T = 125C, = 75C/ W (N) JMAX JA T = 125C, = 100C/ W (SW) JMAX JA Consult factory for Industrial and Military grade parts. ELECTRICAL CHARACTERISTICS V = 12V 5%, T = 25C, unless otherwise noted. DD A SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V V Supply Voltage l 4.5 16 V DD DD I V Supply Current All TTL Inputs = 0V or 5V, No Load on REG l 1200 2000 A DD DD I V Supply Current Power-Down Mode, All TTL Inputs = 0V or 5V l 30 50 A PD DD V Regulator Output Voltage No Load l 3.047 3.072 3.097 V REG LD Regulator Load Regulation Sourcing Only, I = 0mA to 2mA 1 5 mV/mA REG REG LI Regulator Line Regulation No Load, V = 4.5V to 16V 60 100 V/V REG DD TC Regulator Output Tempco No Load, 0C < T < 70C 50 ppm/C REG A V DAC Output Voltage VR1 = 1, VR0 = 1, 100% Duty Ratio, I = I (Note 7) 140 160 180 mV DAC CHRG VR1 = 1, VR0 = 0, 100% Duty Ratio, I = I/3 48 55 62 mV CHRG VR1 = 0, VR0 = 1, 100% Duty Ratio, I = I/5 30 34 38 mV CHRG VR1 = 0, VR0 = 0, 100% Duty Ratio, I = I/10 16 18 21 mV CHRG V Fault Comparator Hysteresis V = 1V, V = 0.9V, V = 100mV 20 mV HYST HTF EDV BATR V = V = 2V 10 mV MCV LTF V Fault Comparator Offset V = 1V, V = 0.9V, V = 100mV 50 mV OS HTF EDV BATR V = V = 2V MCV LTF V V for BATR = 1 100 mV BATR BAT V V for BATP = 1 l V 1.8 V BATP BAT DD V Internal EDV Voltage l 860 900 945 mV EDV V , V LTF, MCV Voltage Range 1.6 2.8 V LTF MCV V HTF Voltage Range 0.5 1.3 V HTF A Gas Gauge Gain 0.4V < V < 0V 4 GG SENSE V Gas Gauge Offset 0.4V < V < 0V (Note 6) 1 LSB OS(GG) SENSE R Internal Filter Resistor 1000 F TOL Battery Divider Tolerance All Division Ratios l 2 2 % BATD V Input Low Voltage CLK, CS, D l 0.8 1.3 V IL IN V Input High Voltage CLK, CS, D l 1.7 2.4 V IH IN I Low Level Input Current V , V or V = 0V l 2.5 2.5 A IL CLK CS DIN I High Level Input Current V , V or V = 5V l 2.5 2.5 A IH CLK CS DIN 2 U W U W U WW