Fuel gauge IC protects against counterfeit batteries
Claimed to be its most advanced battery protector with integrated fuel gauges, Maxim Integrated has introduced the one cell, pack-side MAX17301 and MAX17311 IC. They offer, says Maxim, the most configurable settings for battery safety in the industry and allow fine tuning of voltage and current thresholds based on various temperature zones.
The ICs also offer a first-of-its-kind secondary protection scheme in case the primary protection fails. This secondary protection scheme permanently disables the battery by over-riding a secondary protector or blowing a fuse in severe fault conditions.
ICs are equipped with Maxim’s patented ModelGauge m5 EZ algorithm that delivers highest state-of-charge (soc) accuracy that on average offers 40 per cent better accuracy than competitive offerings and eliminates the need for battery characterisation. The fuel gauges is also claimed to offer the industry’s lowest quiescent current (IQ) – up to 80 per cent lower than the nearest competitor, and feature SHA-256 authentication to safeguard the systems from counterfeit batteries.
Conventional battery protectors monitor voltage and current, and in some cases include temperature monitoring. These options make the system vulnerable to unexpected crashes because battery soc is not factored in when triggering an under-voltage cut-off decision. At present there is no means for deeper configuration of voltage or current thresholds based on multiple temperature environments. As battery-operated applications increase, there is a need for a simple, compact solution that protects from unsafe charging conditions that can lead to extensive battery damage including over-voltage, short circuit, over- or under-temperature scenarios. System and battery designers continue to push the limits of capacity-constrained batteries to provide the longest possible run-time without damaging the cell and designers are also looking for a way to protect the system by ensuring that only genuine batteries are used. This can eliminate unexpected shutdowns and crashes caused by potentially unsafe, counterfeit batteries.
The MAX17301 and MAX17311 fuel gauges integrate a protector that has the most configurable settings for battery safety, says Maxim. These are the only one-cell fuel gauges in the market that offer two-level Li-ion protection, providing an additional layer of security in case the primary protector fails. The compact ICs offer integrated protection capability that helps system makers meet new product safety standards such as IEC 62368-1/UL 62368-1. They offer low-state-based protectors as an alternative to simple low-voltage thresholds, which prevents nuisance tripping in the case of short duration voltage dips due to pulse loads on the battery. They also provide the highest soc accuracy without requiring battery characterisation, eliminating several weeks of time required for sending a battery to a lab for characterisation and analysis.
The low IQ supports long product shelf-life and runtime with operating IQ of 24 microA active/18 microA low power with protector FETs on and 7microA with protector FETs off.
