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Piezoelectric energy harvesting power supply

Linear Technology has announced the LTC3588-1, a complete energy harvesting solution optimised for low energy sources, including piezoelectric transducers. The device integrates a low-loss, full-wave bridge rectifier with a high efficiency buck converter to harvest ambient vibrational energy via piezoelectric transducers and then convert it to a well-regulated output to power application microcontrollers, sensors, data converters and wireless transmission components. The device operates from an input voltage range of 2.7 to 20V, making it suitable for a wide array of piezoelectric transducers, as well other high output impedance energy sources. Its high efficiency buck DC/DC converter delivers up to 100mA of continuous output current or even higher pulsed loads. Its output can be programmed to one of four (1.8, 2.5, 3.3 or 3.6V) fixed voltages to power a wireless transmitter or sensor. Quiescent current is only 950nA with the output in regulation (at no load), maximising overall efficiency.

The device is designed to interface directly with a piezoelectric or alternative AC power source, rectify a voltage waveform and store harvested energy in an external storage capacitor while dissipating any excess power via an internal shunt regulator. An ultralow quiescent current (450nA) undervoltage lockout mode with a wide hysteresis window enables charge to accumulate on the storage capacitor until the buck converter can efficiently transfer a portion of the stored charge to the output. In its no load sleep state, the device regulates the output voltage, consuming 950nA of quiescent current while continuously charging the storage capacitor. The device requires minimal external components and is packaged in either a 3x3mm DFN or a thermally enhanced MSOP10 package, providing a compact solution footprint for a range of energy harvesting applications. The LTC3588EDD-1 is available in a 3x3mm DFN package and the LTC3588EMSE-1 is available in a thermally enhanced MSOP10 package.