I C Battery Gas Gauges 2 CHARGER LOAD LTC2942-1 HOST I2C + REGISTER – Measure Charge, Voltage and Temperature For applications requiring accurate battery gas gauging, the LTC®2941 and LTC2942 coulomb counters provide tiny and easy-to-use solutions. The LTC2941/LTC2942 use a continuous-time analog integrator, resulting in minimal offset and gain error and better overall charge accuracy. The bidirectional analog integrator accommodates both battery charge and discharge, and a programmable prescaler allows for a wide range of battery capacities. The LTC2942 incorporates a 14-bit ∆∑ ADC to measure battery voltage and die temperature. The LTC2941-1 and LTC2942-1 also integrate a 50mΩ sense resistor to provide up to ±1A measurement range. Charge, voltage* and temperature* are all communicated to the host system over an I2C/SMBus compatible interface. Features Linear Technology I2C Battery Gas Gauges Indicates Accumulated Battery Charge and Discharge SMBus/I2C Interface 14-Bit ADC Measures Battery Voltage and Temperature (*LTC2942) High Side Current Sense with ±50mV Sense Range Integrated 50mΩ High Side Sense Resistor with ±1A Range (LTC2941-1/LTC2942-1) 1% Voltage and Charge Accuracy ±50mV Sense Voltage Range Programmable High/Low Thresholds for All Measured Parameters Configurable Alert Output/Charge Complete Input Quiescent Current <100µA LTC2941/ LTC2941-1 LTC2942/ LTC2942-1 Operating Voltage Range 2.7V to 5.5V 2.7V to 5.5V Voltage and Temperature Measurement No Yes Integrated Sense Resistor No/Yes No/Yes 2mm × 3mm DFN-6 2mm × 3mm DFN-6 n n n n n Package n n n n n Total Charge Error (TCE) Over Temperature Part LTC2942-1 LTC2942 L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and PowerPath and Bat-Track are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Sense Resistor TCE N/A 2.8% ±1%, 100ppm/°C ($0.10) 5.1% ±0.1%, 50ppm/°C ($0.30) 3.9% ±0.1%, 15ppm/°C ($3.75) 3.6% Power Manager Products for Li-Ion Batteries The LTC2941/LTC2942 battery gas gauges are ideal companions to Linear Technology’s extensive family of single-cell Li-Ion battery chargers and USB power managers. Pairing with the LTC4099 I2C controlled USB power manager/charger provides a powerful combination that enables I2C programmability of charge functions and complete I2C monitoring of battery state-of-charge information. 3.3µH USB SW VBUS 10µF VOUT LOAD 22µF IDGATE LTC4099 BAT 3.3V DVCC VDD µP 0.1µF 2k 2k SENSE+ SENSE– LTC2942-1 AL/CC IRQ SDA CLPROG PROG GND NTC SCL 1 CELL Li-Ion SDA SCL GND 0.1µF 3.01k 2k USB Power Managers for 1-Cell Li-Ion/Polymer Batteries The LTC4099’s switchmode topology features PowerPath™ control, which seamlessly manages power flow between a wall adapter or USB port and the device’s Li-Ion/Polymer battery, while preferentially providing power to the system load. This revolutionary input current-limited switching regulator design allows higher charge current than conventional linear approaches, while meeting USB specifications. Maximum Charge Current (A) Power Manager Topology Input Voltage (V) Optional External Ideal Diode Controller LTC4055/ LTC4055-1 1 Linear 4.3 to 5.5 No 4mm × 4mm QFN-16 Bat-Track™, LTC4055-1 Has 4.1V VFLOAT LTC4160/ LTC4160-1 1.2 Switching 4.35 to 5.5 Yes 3mm × 4mm QFN-20 Bidirectional Switcher Generates 5V at 0.5A for USB On-the-Go Applications, 6.1V OVP, Bat-Track, Instant-On Operation, LTC4160-1 Has 4.1V VFLOAT LTC4089 1.2 Linear 4.35 to 5.5 USB, 6 to 36 Wall (40V Max) Yes 3mm × 6mm DFN-22 Bat-Track, Instant-On Operation LTC4089-1/ LTC4089-5 1.2 Linear 4.35 to 5.5 USB, 6 to 36 Wall (40V Max) Yes 3mm × 6mm DFN-22 Instant-On Operation, LTC4089-1 Has Bat-Track and for 4.1V Li-Ion, LTC4089-5 Has 5V Output and for 4.2V Li-Ion LTC4067 1.25 Linear 4.35 to 5.5 Yes 3mm × 4mm DFN-14 13V OVP LTC4088/ LTC4088-1/ LTC4088-2 1.5 Switching 4.25 to 5.5 Yes, 30mΩ 3mm × 4mm DFN-14 Bat-Track, charge current reduces to maintain 3.6V output at load. LTC4088 has 3.3V LDO while LTC4088-1 and LTC4088-2 do not. Power-up charger state is off for LTC4088-1 and on for LTC4088-2. LTC4098/ LTC4098-1 1.5 Switching 4.35 to 5.5 USB, Up to 38V Wall (60V Abs Max) Yes, 30mΩ 3mm × 4mm QFN-20 66V OVP, Bat-Track, Instant-On Operation, LTC4098-1 Has 4.1V VFLOAT LTC4099 1.5 Switching 4.35 to 5.5 USB, Up to 38V Wall (60V Abs Max) Yes, 30mΩ 3mm × 4mm QFN-20 I2C Control, Overtemperature Battery Conditioning Circuit, 66V OVP, Bat-Track, Instant-On Operation LTC4090/ LTC4090-5 1.5 Linear 4.35 to 5.5 USB, 6 to 36 Wall (60V Max) Yes 3mm × 6mm DFN-22 Bat-Track, Instant-On Operation, LTC4090-5 Has 5V Output and No Bat-Track LTC4066/ LTC4066-1 1.5 Linear 4.3 to 5.5 No 4mm × 4mm QFN-24 LTC4066-1 Has 4.1V VFLOAT LTC4085/ LTC4085-1/ LTC4085-3 1.5 Linear 4.35 to 5.5 Yes, 50mΩ 3mm × 4mm DFN-14 LTC4085-1 Has 4.1V VFLOAT, LTC4085-3 Has 3.95V VFLOAT LTC4155 3.5 Switching 4.35 to 5.5 USB, 77V OVP Yes ‡ 4mm × 5mm QFN-28 I2C Control, USB OTG, VFLOAT = 4.05V/4.1V/4.15V/4.2V LTC4156 ˆ † 3.5 Switching 4.35 to 5.5 USB, 77V OVP Yes ‡ 4mm × 5mm QFN-28 I2C Control, USB OTG, VFLOAT = 3.45V/3.55V/3.6V/3.8V for Lithium Iron Phosphate Part Number Package Comments and Features ˆ Future product, contact factory for details. †LiFePO compatible. 4 ‡ Required external PFET serves as ideal diode. www.linear.com/2942 n 1-800-4-LINEAR 1111B