Fuel gauge eliminates battery characterisation to speed time to market
Incorporating an algorithm that converts raw measurements like battery voltage, current and temperature in state of charge (%), absolute capacity (mAhr) and time-to-empty, time-to-full (while charging) values, the ModelGauge m5 standalone fuel gauge has been announced by Maxim Integrated.
Consisting of models MAX17201/MAX17205 and MAX17211/MAX17215 the fuel gauges’ EZ configuration eliminates the characterisation process for a large number of battery types. In addition, they are the industry’s first to integrate SHA-256 for secure authentication to prevent battery clones, says the company.
The algorithm detects the smallest changes in the capacity of the battery to predict how long the battery will last before the capacity degrades rapidly. With the Cycle+ age forecast information from the fuel gauges, system designers are able to adjust charger parameters to extend the battery life, or to plan a timely replacement of the battery. The gauges can be used for any rechargeable battery operated device, such as wearables, drones, tablets, smartphones, and other IoT applications, says the company.
There is no need to reset to track battery usage correctly. The gauge learns capacity without battery going to full, empty, or relaxed state. The SHA-256 authentication is combined with a 160bit secret key, which the company says, makes it harder to clone battery packs.
The MAX17201/MAX17211 operates at a low quiescent current of 9microA and the MAX17205/MAX17215 operates at 12microA low-power operation.
The gauges are available in a 14pin, TDFN package, measuring 3.0 x 3.0mm. Operation is over the -40 to +85 degree C range.
Evaluation kits are also available (MAX17201GEVKIT, MAX17205GEVKIT, MAX17211GEVKIT and MAX17215GEVKIT).