DS2438Z+

Product Summary

The DS2438Z+ is a Smart Battery Monitor. The DS2438Z+ provides several functions that are desirable to carry in a battery pack: a means of tagging a battery pack with a unique serial number, a direct-to-digital temperature sensor which eliminates the need for thermistors in the battery pack, an A/D converter which measures the battery voltage and current, an integrated current accumulator which keeps a running total of all current going into and out of the battery, an elapsed time meter, and 40 bytes of nonvolatile EEPROM memory for storage of important parameters such as battery chemistry, battery capacity, charging methodology and assembly date. Information is sent to/from the DS2438Z+ over a 1-Wire interface, so that only one wire (and ground) needs to be connected from a central microprocessor to a DS2438Z+. This means that battery packs need only have three output connectors: battery power, ground, and the 1-Wire interface.

Parametrics

DS2438Z+ absolute maximum ratings: (1)Voltage on VDD and VAD, Relative to Ground: -0.3V to + 12V; (2)Voltage on VSENS+, VSENS-, Relative to Ground: <±300 mV; (3)Voltage on Any Other Pin Relative to Ground: -0.3V to + 7.0V; (4)Operating Temperature: -40 to +85℃; (5)Storage Temperature: -55 to +125℃.

Features

DS2438Z+ features: (1)Unique 1-Wire interface requires only one port pin for communication; (2)Provides unique 64-bit serial number; (3)Eliminates thermistors by sensing battery temperature on-chip; (4)On-board A/D converter allows monitoring of battery voltage for end-of-charge and end-of-discharge determination; (5)On-board integrated current accumulator facilitates fuel gauging; (6)Elapsed time meter in binary format; (7)40-byte nonvolatile user memory available for storage of battery-specific data; (8)Reverts to low-power sleep mode on battery pack disconnect; (9)Operating range -40 to +85℃; (10)Applications include portable computers, portable/cellular phones, consumer electronics, and handheld instrumentation.

Diagrams