19-4637 5/09 DS2786 Stand-Alone OCV-Based Fuel Gauge www .maxim-ic.com GENERAL DESCRIPTION FEATURES The DS2786 estimates available capacity for Relative Capacity Calculated from rechargeable Li-Ion and Li-Ion Polymer batteries Combination Coulomb Counter and Open- based on the cell voltage in the open-circuit state Circuit Cell Voltage (OCV) Battery Model following a relaxation period. The open-circuit voltage Accurate Warning of Low Battery Conditions (OCV) is used to determine relative cell capacity Even On First Cycle (No Learn Cycle Needed) based on a lookup table stored in the IC. This 12-Bit Battery Voltage Measurement: capability makes accurate capacity information 10mV Accuracy available immediately after a battery pack is inserted. 1.22mV LSB, 0V to 4.5V Input Range During periods of moderate to high rate discharging, 11-Bit Bidirectional Current Measurement: which preclude OCV measurements, the DS2786 25 V LSB, 51.2mV Dynamic Range uses coulomb counting as a secondary means of 1.67mA LSB, 3.4A (R = 15m) SNS estimating relative capacity. Current Accumulation Measurement Resolution: Remaining capacity is reported in percent, along with 204.8mVh Range cell voltage, current and temperature information. 13.65Ah (R = 15m) SNS Cell characteristics and application parameters used Internal Temperature Measurement: in the calculations are stored in on-chip EEPROM. 0.125C LSB, 3C Accuracy Two 11-Bit Aux Input Voltage Measurements: The DS2786 is intended for use on the host side of 8 LSB Accuracy, Ratiometric Inputs portable devices, though it can also be mounted Eliminate Supply Accuracy Issues within a battery pack. Measurement and estimated V Pin Drives Resistive Dividers, Reduces 2 OUT capacity data are accessed through an I C interface. Current Consumption Temperature data is available from an on-die sensor. 2-Wire Interface Resistance measurements of a pack identification Low Power Consumption: resistor and pack thermistor are supported by Active Current: 50 A typ, 80 A max ratiometric measurements on two auxiliary inputs. Sleep Current: 1 A typ, 3 A max APPLICATIONS ORDERING INFORMATION 3G Multimedia Wireless Handsets PART TEMP RANGE PIN-PACKAGE Digital Still Cameras DS2786G+ -20C to +70C 10 TDFN-EP* Digital Audio (MP3) Players DS2786G+T&R -20C to +70C 10 TDFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. TYPICAL OPERATING CIRCUIT T&R = Tape and reel. *EP = Exposed pad. PIN CONFIGURATION 3mm x 3mm TDFN-10 Commands, Registers, and Modes are capitalized for clarity. Top View 1 of 22 DS2786 Stand-Alone OCV-Based Fuel Gauge ABSOLUTE MAXIMUM RATINGS Voltage Range on All Pins Except V Relative to V -0.3V to +6V PROG SS Voltage Range on V Relative to V -0.3V to +18V PROG SS Operating Temperature Range -40C to +85C Storage Temperature Range -55C to +125C Soldering Temperature Refer to the IPC/JEDECJ-STD-020 Specification. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. RECOMMENDED DC OPERATING CONDITIONS (2.5V V 4.5V, T = -20 C to +70C.) DD A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage V (Note 1) +2.5 +4.5 V DD Data I/O Pins SCL, SDA (Note 1) -0.3 +4.5 V Programming Pin V (Note 1) -0.3 +15.5 V PROG V , AIN0, IN VIN, AIN0, AIN1 Pin (Note 1) -0.3 V + 0.3 V DD AIN1 DC ELECTRICAL CHARACTERISTICS (2.5V V 4.5V, T = -20 C to +70C, unless otherwise noted.) DD A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 75 Active Current I 50 A ACTIVE V = 2.0V, DD 0.3 1.0 SCL, SDA = V SS Sleep-Mode Current I A SLEEP SCL, SDA = V 1 3 SS Current Measurement I DS2786 25 V LSB Resolution Current Measurement I (Note 1) 51.2 mV FS Full-Scale Magnitude Current Measurement I DS2786 (Note 2) -50 +50 V OERR Offset Error Current Measurement % of I -1.5 +1.5 GERR Gain Error reading V = 3.6V at +25C -1 +1 DD Timebase Accuracy t -2 +2 % ERR T = 0 C to +70C A -3 +3 T = -20 C to +70C A V = V = 3.6V, DD IN -10 +10 T = 0 C to +50C A Voltage Error V mV GERR -20 +20 T = -20 C to +70C A Input Resistance R 15 M IN VIN, AIN0, AIN1 AIN0, AIN1 Error -8 +8 LSB V Output Drive I = 1mA V - 0.5 V OUT O DD 2 of 22