LTC1760 Dual Smart Battery System Manager FEATURES DESCRIPTION n SMBus Charger/Selector for Two Smart Batteries* The LTC 1760 Smart Battery System Manager is a highly- n integrated SMBus Level 3 battery charger and selector Voltage and Current Accuracy within 0.2% of Value intended for products using dual smart batteries. Three Reported by Battery n SMBus interfaces allow the LTC1760 to servo to the Simplifies Construction of Smart Battery System internal voltage and currents measured by the batteries Manager while allowing an SMBus Host device to monitor either n Includes All SMBus Charger V1.1 Safety Features batterys status. Charging accuracy is determined by the n Supports Autonomous Operation without a Host batterys internal voltage and current measurements, n Allows Both Batteries to Discharge Simultaneously typically better than 0.2%. into Single Load with Low Loss (Ideal Diode) n A proprietary PowerPath architecture supports simultane- SMBus Switching for Dual Batteries with Alarm ous charging or discharging of both batteries. Typical battery Monitoring for Charging Battery at All Times run times are extended by up to 10%, while charging times n Pin Programmable Limits for Maximum Charge are reduced by up to 50%. The LTC1760 automatically Current and Voltage Improve Safety switches between power sources in less than 10s to prevent n Fast Autonomous PowerPath Switching (<10s) power interruption upon battery or wall adapter removal. n Low Loss Simultaneous Charging of Two Batteries n >95% Efficient Synchronous Buck Charger The LTC1760 implements all elements of a version 1.1 n Smart Battery System Manager except for the generation AC Adapter Current Limiting* Maximizes Charge Rate n of composite battery information. An internal multiplexer SMBus Accelerator Improves SMBus Timing** cleanly switches the SMBus Host to either of the two n Available in 48-Lead TSSOP Package attached Smart Batteries without generating partial mes- sages to batteries or SMBus Host. Thermistors on both APPLICATIONS batteries are automatically monitored for temperature and n Portable Computers and Instruments disconnection information (SafetySignal). n Standalone Dual Smart Battery Chargers L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and PowerPath is a trademark of Analog Devices, Inc. All other trademarks are the property of their n Battery Backup Systems respective owners. Protected by U.S. Patents including *5723970 **6650174. TYPICAL APPLICATION Dual Battery Charger/Selector System Architecture Dual vs Sequential Charging DC 3500 BAT2 BAT1 IN 3000 CURRENT CURRENT 2500 2000 SEQUENTIAL 1500 SYSTEM POWER 1000 500 0 3500 LTC1760 BAT1 3000 CURRENT SMBus (HOST) 2500 BAT2 2000 CURRENT DUAL 1500 1000 100 500 SafetySignal 1 MINUTES 0 0 50 100 150 200 250 300 SMBus 1 TIME (MINUTES) BATTERY TYPE: 10.8V Li-Ion (MOLTECH NI2020) REQUESTED CURRENT = 3A SafetySignal 2 REQUESTED VOLTAGE = 12.3V MAX CHARGER CURRENT = 4.1A 1760 TA03 SMBus 2 1760 TA01 1760fc 1 For more information www.linear.com/LTC1760 BATTERY CURRENT (mA)LTC1760 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW DCIN, SCP, SCN, CLP, V 1 48 SCH2 PLUS V , SW to GND ..................................... 0.3V to 32V PLUS BAT2 2 47 GCH2 BAT1 3 46 GCH1 SCH1, SCH2 to GND ................................... 0.3V to 28V SCN 4 45 SCH1 BOOST to GND ........................................... 0.3V to 37V SCP 5 44 TGATE GDCO 6 43 BOOST CSP, CSN, BAT1, BAT2 to GND ................... 0.3V to 28V GDCI 7 42 SW LOPWR, DCDIV to GND ............................. 0.3V to 10V GB1O 8 41 DCIN GB1I 9 40 V CC V , V to GND .......................................0.3V to 7V CC2 DDS GB2O 10 39 BGATE GB2I 11 38 PGND SDA1, SDA2, SDA, SCL1, LOPWR 12 37 COMP1 SCL2, SCL, SMBALERT to GND ....................0.3V to 7V V 13 36 CLP SET I 14 35 CSP MODE to GND .................................0.3V to V +0.3V TH CC2 I 15 34 CSN SET COMP1 to GND ............................................ 0.3V to 5V DCDIV 16 33 V LIMIT SCL2 17 32 I LIMIT Maximum DC Current Into Pin SCL 18 31 TH1B SDA1, SDA2, SDA, SCL1, SCL2, SCL ................ 3mA SCL1 19 30 TH1A V 20 29 SMBALERT DDS TH1A, TH2A ..................................................... 5mA SDA2 21 28 TH2A TH1B, TH2B ................................................... 102A SDA 22 27 TH2B SDA1 23 26 MODE Operating Junction Temperature Range GND 24 25 V CC2 (Note 6) .................................................. 40C to 125C FW PACKAGE 48-LEAD PLASTIC TSSOP Storage Temperature.............................. 65C to 150C T = 125C, q = 110C/W JMAX JA Lead Temperature (Soldering, 10 sec) ...................300C ORDER INFORMATION (