All three functions are optimised for ultra-low-power applications using a single-cell Lithium-ion battery as a power source. The battery charger operates across an input voltage of 4V to 6.5V, while the step-down converter and LDO operate across a 2.7V to 5.5V input range. As a complete constant current / constant voltage linear device, the battery charger delivers a programmable constant current up to 500mA. It features reverse blocking protection and high current accuracy, as well as voltage regulation, charge status, and charge termination functions.
Using a high, 1.5MHz switching frequency, the step-down converter also helps minimise system footprint by supporting the use of extremely small external components. The converter functions using an inductor of less than 1mm in height, while delivering 250mA output current with an efficiency as high as 96 percent.
The LDO integrated into the AAT2554 can supply up to 300mA output current. It features fast line and load transient response and a low 70µA quiescent current. To ensure safe device operation, the AAT2554 also features short-circuit, over-temperature, and current limit protection circuits.
The AAT2554 is the third production device introduced using AnalogicTech’s ModularBCD process technology. Unlike conventional BCD technologies, ModularBCD uses a low-temperature, CMOS-like flow capable of achieving high yields while ensuring device performance and electrical isolation. By allowing AnalogicTech’s designers to easily add or remove modules and devices for different voltages, this highly modular new process vastly simplifies analogue and mixed-signal circuit reuse.
A growing number of new portable electronic products, such as Bluetooth® headsets and handheld GPS devices, operate from a single Lithium-ion cell and must efficiently charge the battery and power a small microprocessor, its I/O, and other analogue circuitry. By combining the aforementioned three functions, specifically sized for low-power environments, into a single package, the AAT2554 helps designers meet stringent system footprint constraints, reduce component count, and simplify their design.
Specified over the -40 to +85 degrees C temperature range, the AAT2554 is available now in a Pb-free, 16-pin, 3x4mm TDFN package.