Active self supplied AC-DC converter for piezoelectric energy scavenging systems with supply independent bias

Abstract

Abstract-The paper focuses on an electronic interface which can be used into Piezoelectric Energy Scavenging Systems (PESS). These systems convert the energy of mechanical vibrations into electrical energy using a piezoelectric transducer to realize a power supply for low power electronic systems. To obtain a suitable supply source an AC-DC conversion of the output signal of these transducers is needed and, since the output power level of the energy scavenger can be very low, the conversion should be as efficient as possible. This paper shows an active voltage doubler AC-DC converter for PESSs. A novel driving circuitry topology is presented; it has the advantage to be tolerant with respect to the process variations. The converter uses exclusively a fraction of the harvested energy to supply itself and a bias circuit has been designed to make the total current consumption supply independent. The simulation results show that the efficiency of the AC-DC converter can be as high as 94%. The circuit will be diffused in 0.35µm CMOS STMicroelectronics technology.

Energy harvesting from low frequency applications using piezoelectric materials

“…Dallago et al used an active voltage doubler to rectify in the energy harvesting system. 104,105 Although the voltage doubler rectifier could generate two times the output voltage compared to full-wave bridge rectifiers, it could only provide the output current during positive half-cycle of the input. For this reason, Ramadass and Chandrakasan presented two additional types of rectifiers, called "switch-only" and "Bias-flip" rectifiers, respectively ( Figure 15).…”

An Efficient Piezoelectric Energy Harvesting Interface Circuit Using a Bias-Flip Rectifier and Shared Inductor

“…The diode used in the simulation was obtained using a pMOS transistor with its source as the anode and the gate, drain and bulk connected together as the cathode of the diode. Considerable work [5], [12]- [14] has been done on using synchronous rectifiers that use MOS transistors to replace the diodes. These have much lower forward voltage loss compared to p-n junction diodes or transistor-based diodes.…”

A Self-Biased Active Voltage Doubler for Energy Harvesting Systems

“…But single supply op-amp needs appropriate signal biasing; otherwise the op-amp becomes unstable or does not provide the desired output. A single supply differential pair MOS configuration [15] is adopted as shown in Figure 5.…”