The fuel pressure gauge interface of the digitally controlled MAX1660 performs two basic functions for rechargeable battery pack management: fuel gauge, and pack overcurrent protection. It accurately monitors the charging and discharging current flowing through the battery pack and records each using two independent on-board coulomb counters. The contents of each counter are accessed through an external System Management Bus (SMBus™) compatible 2-wire serial interface. An optional third line interrupts the microcontroller (µC) when the charge or discharge counter reaches a preset value, or when an overcurrent condition (charge or discharge) occurs. In the event of an overcurrent or short-circuit condition, the MAX1660 disconnects the load and its host alarms. The flexibility of the MAX1660 allows accurate fuel gauge chemistry for any battery, using any desired control algorithm. The MAX1660 operates from a +4 V battery voltage to +28 V and provides two micropower shutdown modes to increase battery life. To minimize total parts count, the device integrates an accurate 2.00V system reference output, a 3.3V linear regulator output that can provide up to 5mA to power external circuits, and a power system μC reset output. "The MAX1660 is available in a 16-pin QSOP package.

Features © 1% accuracy over 600µA 4A current range (RSENSE = 30m half)
© 5μV input offset voltage (28μV max)
© SMBus 2-wire (plus optional interrupt) serial interface © 2.00V Precision System Reference Output © 3.3V Linear Regulator Output Power External Circuit © Two Micropower Shutdown Modes © Independent 32-Bit Charge-Discharge Coulomb Counter © Battery-Overcharge/Overdischarge Protection © Battery Short-Circuit/Overcurrent Protection © On-Board Power MOSFET Drivers © 80µA Quiescent Current © <1µA Shutdown Current SO