LTC3588-1 and LTC3588-2 Piezoelectric Energy Harvesting Power Supplies

Analog Devices' LTC3588-1 and LTC3588-2 integrate a low-loss full-wave bridge rectifier with a high efficiency buck converter to form a complete energy harvesting solution optimized for high output impedance energy sources such as piezoelectric transducers. With the LTC3588-1, an ultralow quiescent current undervoltage lockout (UVLO) mode with a wide hysteresis window allows charge to accumulate on an input capacitor until the buck converter can efficiently transfer a portion of the stored charge to the output. In regulation, the LTC3588-1 enters a sleep state in which both input and output quiescent currents are minimal. The buck converter turns on and off as needed to maintain regulation. With the LTC3588-2, an ultralow quiescent current undervoltage lockout (UVLO) mode with a 16 V rising threshold enables efficient energy extraction from piezoelectric transducers with high open circuit voltages. This energy is transferred from the input capacitor to the output via a high efficiency synchronous buck regulator. The 16 V UVLO threshold also allows for input to output current multiplication through the buck regulator. The buck features a sleep state that minimizes both input and output quiescent currents while in regulation.