Full-Wave Rectifier for Vibration Energy Harvesting

Low-Power Piezoelectric Harvesting Full-Wave Rectifier with Vibration-Triggered Comparator Switching

This technology is a vibration energy harvesting rectifier circuit that incorporates a vibration sensor to activate the active diode comparator only when vibration is present. The vibration sensor consists of a peak detector using diodes and capacitors, along with a two-stage inverter level shifter.

Diode rectifiers suffer from high voltage drops, while MOSFET rectifiers are limited by leakage current. Improved two-stage active diode full-wave rectifiers still faced issues where the comparator power was connected to the storage capacitor, causing the comparator to continuously drain stored energy even when there was no vibration or output.

When the peak detector output is '0', this technology uses two active/inactive switches to turn off the comparator. Signals lowered by diode drops are restored to digital signals even below half the supply voltage using a level shifter with an added PMOS resistor. It can be applied to vibration harvesting power supplies for wireless sensor node batteries and IoT monitoring devices, preventing energy leakage during periods of inactivity to extend sensor operation time.

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Key Features:

• Full-wave rectifier for vibration energy harvesting that converts AC voltage from a piezoelectric transducer into DC voltage
• Vibration sensor that detects the presence of vibration from the piezoelectric transducer output and sends activation or deactivation signals to the active diode comparator
• Configuration that detects peaks using a diode and parallel capacitor, and restores digital signals via a two-stage inverter level shifter with an added PMOS resistor
• Configuration that disables the comparator using two active/inactive switches when the vibration detection signal is 0, cutting off rectifier power consumption

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This invention was developed with support from the Ministry of Science, ICT and Future Planning for the implementation of self-powered wireless sensor nodes through the development of multi-input micro energy harvesters and energy/power management SoCs.

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