MAX17320 Fuel Gauge with Protector

ADI's MAX17320 is a 38 µA I_Q stand-alone pack-side fuel gauge IC with protector, battery internal self-discharge detection, and optional SHA-256 authentication for 2 to 4 series lithium-ion/polymer batteries.

The IC monitors the voltage, current, temperature, and state of the battery to provide protection against over/undervoltage, overcurrent, short-circuit, over/undertemperature, overcharge, and internal self-discharge conditions using external high-side N-FETs, and provides charging prescription to ensure that the battery operates under safe conditions, thereby prolonging the life of the battery. The IC balances the cells using internal FETs. During prequalification charging, the IC uses the CHGFET to linearly control charging.

To prevent battery pack cloning, the IC integrates SHA-256 authentication with a 160-bit secret key. Each IC incorporates a unique 64-bit ID.

The fuel gauge uses Analog Devices' ModelGauge™ m5 algorithm that combines the short-term accuracy and linearity of a coulomb counter with the long-term stability of a voltage-based fuel gauge to provide industry-leading fuel gauge accuracy. The IC automatically compensates for cell aging, temperature, and discharge rate, and provides accurate state-of-charge (SOC) in milliampere hours (mAh) or percentage (%) over a wide range of operating conditions.

The IC provides a configurable always-on LDO that can power small critical loads on the system side without overloading the cells, even under fault conditions. Dynamic power functionality provides the instantaneous maximum battery output power, which can be delivered to the system without violating the minimum system input voltage.

A 1-Wire® or 2-wire I²C/SMBus interface provides access to data and control registers. The IC is available in lead-free, 2.4 mm x 2.6 mm 30-bump 0.4 mm pitch WLP and 4 mm x 4 mm 24-pin TQFN packages.