Low-Cost Battery Monitor Includes I2C Interface

Debuting as an economical Li battery monitor, the DS2745 integrates an I2C interface and mounts on either the host or battery-pack side of the application to provide current, voltage, and temperature measurements. Current measurements occur bidirectionally over a dynamic range of ±51.2 mV with a resolution of 1.56 µV by monitoring the voltage drop across an external sense resistor. When using a 15 mO resistor, current-sensing range is ±3.4A with a 1 LSB resolution of 104 µA. Battery voltage is measured through a voltage-sense input and appears in a two-byte register with an 11-bit resolution. Temperature measurements are made via a two-byte register with a resolution of 0.125°C. Available in an eight-pin microMAX package, the device operates with an active power consumption of less than 70 µA and less than 1 µA in sleep mode. Price is $0.98 each. MAXIM INTEGRATED PRODUCTS INC., Dallas, TX. (800) 998-8800.