Linear Technology Releases I²C Battery Gas Gauge Operates up to 20V
The LTC2943 Measures Charge, Voltage, Current and Temperature to within 1% Accuracy
Linear Technology has released the LTC2943, multicell battery gas
gauge which makes direct measurements of 3.6V to 20V battery stacks. Absolutely no level shifting circuitry on the
supply and measurement pins is required to interface with multicell voltages, so total current consumption is
minimized and measurement accuracy is preserved. The LTC2943 is a true high voltage gas gauge that measures
charge, voltage, current and temperature to within 1% accuracy - all of the essential parameters required to
accurately assess battery state of charge (SoC).
The LTC2943 is best suited for multicell applications, including professional power tools and portable medical equipment. Battery current is measured by monitoring the voltage across an external, high side sense resistor and integrating this information to infer charge. A bidirectional analog integrator accommodates either current polarity (battery charge or discharge), and a programmable prescaler allows for a wide range of battery capacities. Charge, voltage, current and temperature information are communicated to the host system over an I²C/SMBus-compatible 2- wire interface that is also used to configure the gas gauge. The host can program high and low thresholds for all measured parameters, which if tripped, signal an alert using either the SMBus alert protocol or by setting a register flag.
The LTC2943 is offered in commercial and industrial versions, supporting operating temperature ranges from 0°C to 70°C and -40°C to 85°C, respectively. The LTC2943 is available today in a small RoHS compliant, 8-pin 3mm x 3mm DFN package.
Features of the LTC2943 include:
- Measures Accumulated Battery Charge & Discharge
- 3.6V to 20V Operating Range for Multicell Applications
- 14-bit ADC Measures Voltage, Current & Temperature
- 1% Charge, Voltage & Current Accuracy
- ±50mV Sense Voltage Range
- High-Side Sense
- I²C/SMBus Interface
- Configurable Alter Output/Charge Complete Input
- Quiescent Current <120µA
The company's Web site address is www.analog.com.
[Reprinted with kind permission from Linear Technology - Release Date: 29th October, 2013]