This article introduces a new wireless power solution that can harvest ambient mechanical, thermal or electromagnetic energy from a sensor's local environment, eliminating the need for batteries in wireless sensors. This solution uses a piezoelectric transducer to convert mechanical vibration energy into electrical energy, which is then stored in a usable energy reservoir.
The document introduces the LTC3588-1, an integrated power supply solution that combines a low-loss internal bridge rectifier with a synchronous step-down DC/DC converter. It is specifically engineered to manage energy harvested from high-impedance piezoelectric elements, such as those used in vibration-based wireless sensor networks.
The note details the device's operation modes, including an undervoltage lockout (UVLO) phase that draws less than a microamp of quiescent current to accumulate charge on an input capacitor. Once sufficient energy is stored, the internal buck converter transfers power to the output in short bursts. The document also covers design considerations for piezoelectric elements and storage options.
The buck delivers up to 100mA of average load current when switching.
Four output voltages, 1.8V, 2.5V, 3.3V and 3.6V, are pin selectable to accommodate powering of microprocessors.