e-peas markets a new family of battery charger devices fully dedicated to the charging function. The PMICs feature a simpler implementation, where there are space or cost constraints that need to be considered. They are able to achieve zero quiescent current draw from the battery – meaning that if energy harvesting stops for a prolonged period of time, the energy stored into the battery will not be wasted supplying the PMIC.
Working in conjunction with a single-cell photovoltaic panel, the highly-integrated AEM10900 PMIC boost converter is optimized for solar-based energy harvesting implementations. Through its super-fast power point tracking (MPPT) functionality specially set for objects in movement, this device is able to ensure that it gets the most energy from the ambient illumination available – so as much as possible can be stored.
In addition, it has a 250mV cold start capability, which means it can commence with charging the battery even when light intensities are very low. AEM10900 introduces an I2C interface to minimize the pin count and to offer a larger set of potential configurations.
It offers an array of features, including battery thermal protection, a joule counter to let the user know the amount of energy harvested, plus a shipping mode in which the battery cannot be charged. Key applications from this PMIC will be wearable consumer products and body-worn medical monitoring equipment.
AEM10300 and AEM30300 PMICs both have built-in ultra-low power DC/DC converters supporting operation over an input voltage range that covers 100mV to 4.5V. Adaptive energy management permits these devices to automatically switch between boost, buck-boost and buck operational configurations as deemed appropriate. This ensures that optimal energy transfer is always maintained between the respective inputs and the storage element.
All these new battery chargers PMICs only require three external components. This means that energy harvesting functionality can be added while keeping the bill-of-materials costs low and taking up very little board space.
The AEM10300 and AEM30300 PMICs are both supplied in a 28-pin QFN package format (with (4mm x 4mm dimensions), while the AEM10900 is available in either the 28-pin QFN package or a 16-pin WLCSP (with 2mm x 2mm dimensions) package for even greater space savings.
