DS2788 19-4639 Rev 2 5/09 Stand-Alone Fuel-Gauge IC with LED Display Drivers General Description Features The DS2788 measures voltage, temperature, and cur- Five 30mA Open-Drain Drivers for Driving LED rent, and estimates available capacity for rechargeable Fuel-Gauge Display lithium-ion (Li+) and Li+ polymer batteries. Cell charac- Debounced Fuel-Gauge Display Enable teristics and application parameters used in the calcu- lations are stored in on-chip EEPROM. The available Internal Voltage Measurement Gain Register for capacity registers report a conservative estimate of the Trimming External Voltage-Divider amount of charge that can be removed given the cur- Pin for Driving FETs to Enable Voltage-Divider rent temperature, discharge rate, stored charge, and application parameters. Capacity estimation is reported Only During Voltage Measurement, Conserving in mAh remaining and percentage of full. Power LED display drivers and a debounced input make dis- Precision Voltage, Temperature, and Current play of the capacity information easy. The LED pins can Measurement System directly sink current, requiring only a resistor for setting Accurate, Temperature-Stable, Internal Time Base the current in the LED display, thus reducing space and cost. Absolute and Relative Capacity Estimated from Coulomb Count, Discharge Rate, Temperature, Applications and Battery Cell Characteristics Power Tools Accurate Warning of Low Battery Conditions Electric Bicycles Automatic Backup of Coulomb Count and Age Electric Vehicles Estimation to Nonvolatile (NV) EEPROM Uninterruptible Power Supply Gain and Tempco Calibration Allows the Use of Digital Cameras Low-Cost Sense Resistors 24-Byte Battery/Application Parameter EEPROM Pin Configuration 16-Byte User EEPROM Unique ID and Multidrop 1-Wire Interface TOP VIEW 14-Pin TSSOP Package + LED2 1 14 LED3 Ordering Information LED1 2 13 LED4 DV 3 12 LED5 SS PART TEMP RANGE PIN-PACKAGE V PIO DD 4 11 DS2788E+ -25C to +70C 14 TSSOP DS2788 OVD 5 10 V DS2788E+T&R -25C to +70C 14 TSSOP IN +Denotes a lead(Pb)-free/RoHS-compliant package. V 6 9 SNS SS T&R = Tape and reel. DQ 7 8 VMA TSSOP Typical Operating Circuit appears at end of data sheet. 1-Wire is a registered trademark of Maxim Integrated Products, Inc. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.Stand-Alone Fuel-Gauge IC with LED Display Drivers ABSOLUTE MAXIMUM RATINGS Voltage Range on Any Pin Relative to V -0.3V to +6.0V Operating Temperature Range ...........................-40C to +85C SS.............. Voltage Range on V , VMA Relative to V -0.3V to V + 0.3V Storage Temperature Range .............................-55C to +125C IN SS ... DD DV to V -0.3V to +0.3V Soldering Temperature (10s) ................Refer to IPC/JEDEC-020 SS SS..................................................................... LED15.................................................................60mA each pin Specification. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. RECOMMENDED DC OPERATING CHARACTERISTICS (V = 2.5V to 4.5V, T = -25C to +70C, unless otherwise noted. Typical values are at T = +25C.) DD A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage V (Note 1) +2.5 +4.5 V DD V , VMA Voltage Range (Note 1) 0 V V IN DD DQ, PIO, OVD, LED1LED5 (Note 1) 0 +5.5 V Voltage Range DC ELECTRICAL CHARACTERISTICS (V = 2.5V to 4.5V, T = -25C to +70C, unless otherwise noted. Typical values are at T = +25C.) DD A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 2.5V V 4.2V 70 95 DD ACTIVE Current I A ACTIVE 105 SLEEP Mode Current I 1 3 A SLEEP Input Logic-High: DQ, PIO V (Note 1) 1.5 V IH Input Logic-Low: DQ, PIO V (Note 1) 0.6 V IL Output Logic-Low: DQ, PIO, VMA V I = 4mA (Note 1) 0.4 V OL OL V - DD Output Logic-High: VMA V I = 1mA (Note 1) V OH OH 0.5 VMA Precharge Time t 13.3 14.2 ms PRE Pulldown Current: DQ, PIO I V , V = 0.4V 0.2 5 A PD DQ PIO Output Logic-Low: LED1LED5 V I = -30mA (Note 1) 1 V OL OL V - DD Input Logic-High: OVD V (Note 1) V IH 0.2 V + SS Input Logic-Low: OVD V (Note 1) V IL 0.2 V Input Resistance R 15 M IN IN DQ SLEEP Timeout t DQ < V 1.8 2.0 2.2 s SLEEP IL Undervoltage SLEEP Threshold V (Note 1) 2.40 2.45 2.50 V SLEEP PIO Switch Debounce 100 130 ms LED1 Display Blink Rate 50% duty cycle 0.9 1.0 1.1 Hz LED Display-On Time 3.6 4.0 4.4 s 2 DS2788