Efficient power management is a key component for energy harvesting but one of the biggest issues is that consumption from the power management function is greater than the energy supply from the environment.
The AP4470 requires only 0.2V input to start boosting without the need for an external transformer. This helps minimise the size of the energy harvesting materials needed and simplify the structure. The converter has two switches, one that controls the power supply for target devices such as sensors, wireless modules or LEDs and protect external storage such as capacitors, and one for the target. This provides a self-powered wireless sensor node, display system with simple hardware design.
The AP4470 converts DC inputs up to 3.55V and monitors external storage. When the external storage voltage reaches 3.3V, the AP4470 automatically starts suppling to target devices. If the voltage drops down to 2.6V, the AK4470 stops suppling voltage and current via on-chip switch function.
It has two types of power indicators that support a reset function and trigger switch with zero standby current. A pin outputs a signal when the boosting circuit becomes active, while another outputs a signal when the AP4470 starts supplying, which means external storage’s voltage reaches 3.3V.