scholarly journals A Fully Integrated Clocked AC-DC Charge Pump for Mignetostrictive Vibration Energy Harvesting

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2194
Author(s):  
Hayato Kawauchi ◽  
Toru Tanzawa

This paper describes a clocked AC-DC charge pump to enable full integration of power converters into a sensor or radio frequency (RF) chip even with low open circuit voltage magnetostrictive vibration energy transducer operating at a low resonant frequency of 10 Hz to 1 kHz. The frequency of the clock to drive an AC-DC charge pump was up-converted with an on-chip oscillator to increase output power of the charge pump without significantly increasing the circuit area. A model of the system including the charge pump and vibration energy transducer is shown. It was validated by HSPICE simulation and measured, resulting in a prototype chip with an area of 0.11 mm2 fabricated in a 65 nm 1 V CMOS process. The fabricated charge pump was also measured together with a magnetostrictive transducer. The charge pump converted the power from the transducer to an output power of 4.2 μW at an output voltage of 2.0 V. The output power varied below 3% over a wide input frequency of 10 Hz to 100 kHz, which suggests that universal design of the clocked AC-DC charge pump can be used for transducers with different resonant frequencies. In a low-input voltage region below 0.8 V, the proposed circuit has higher output power compared with the conventional circuits.

Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1185
Author(s):  
Yosuke Ishida ◽  
Toru Tanzawa

This paper proposes an AC-DC converter for electrostatic vibration energy harvesting. The converter is composed of a CMOS full bridge rectifier and a CMOS shunt regulator. Even with 1 V CMOS, the open circuit voltage of the energy transducer can be as high as 10 V and beyond. Bandgap reference (BGR) inputs a regulated voltage, which is controlled by the output voltage of the BGR. Built-in power-on reset is introduced, which can minimize the silicon area and power to function normally found upon start-up. The AC-DC converter was fabricated with a 65 nm low-Vt 1 V CMOS with 0.081 mm2. 1 V regulation was measured successfully at 20–70 °C with a power conversion efficiency of 43%.


Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 257 ◽  
Author(s):  
Se-Eun Choi ◽  
Hyunjin Ahn ◽  
Joonhoi Hur ◽  
Kwan-Woo Kim ◽  
Ilku Nam ◽  
...  

This work presents a compact on-chip outphasing power amplifier with a parallel-combining transformer (PCT). A series-combining transformer (SCT) and PCT are analyzed as power-combining transformers for outphasing operations. Compared to the SCT, which is typically used for on-chip outphasing combiners, the PCT is much smaller. The outphasing operations of the transformer combiners and class-D switching PAs are also analyzed. A tuning inductor method is proposed to improve the efficiency of class-D power amplifiers (PAs) with power-combining transformers in the out-of-phase mode. The proposed PA was implemented with a standard 0.18 µm CMOS process. The measured maximum drain efficiency is 37.3% with an output power of 22.4 dBm at 1.7 GHz. A measured adjacent channel leakage ratio (ACLR) of less than −30 dBc is obtained for a long-term evolution (LTE) signal with a bandwidth of 10 MHz.


Electronics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 68
Author(s):  
Woorham Bae ◽  
Sung-Yong Cho ◽  
Deog-Kyoon Jeong

This paper presents a fully integrated Peripheral Component Interconnect (PCI) Express (PCIe) Gen4 physical layer (PHY) transmitter. The prototype chip is fabricated in a 28 nm low-power CMOS process, and the active area of the proposed transmitter is 0.23 mm2. To enable voltage scaling across wide operating rates from 2.5 Gb/s to 16 Gb/s, two on-chip supply regulators are included in the transmitter. At the same time, the regulators maintain the output impedance of the transmitter to meet the return loss specification of the PCIe, by including replica segments of the output driver and reference resistance in the regulator loop. A three-tap finite-impulse-response (FIR) equalization is implemented and, therefore, the transmitter provides more than 9.5 dB equalization which is required in the PCIe specification. At 16 Gb/s, the prototype chip achieves energy efficiency of 1.93 pJ/bit including all the interface, bias, and built-in self-test circuits.


Author(s):  
Alok Ranjan Biswal ◽  
Tarapada Roy ◽  
Rabindra Kumar Behera

The current article deals with finite element (FE)- and genetic algorithm (GA)-based vibration energy harvesting from a tapered piezolaminated cantilever beam. Euler–Bernoulli beam theory is used for modeling the various cross sections of the beam. The governing equation of motion is derived by using the Hamilton's principle. Two noded beam elements with two degrees of freedom at each node have been considered in order to solve the governing equation. The effect of structural damping has also been incorporated in the FE model. An electric interface is assumed to be connected to measure the voltage and output power in piezoelectric patch due to charge accumulation caused by vibration. The effects of taper (both in the width and height directions) on output power for three cases of shape variation (such as linear, parabolic and cubic) along with frequency and voltage are analyzed. A real-coded genetic algorithm-based constrained (such as ultimate stress and breakdown voltage) optimization technique has been formulated to determine the best possible design variables for optimal harvesting power. A comparative study is also carried out for output power by varying the cross section of the beam, and genetic algorithm-based optimization scheme shows the better results than that of available conventional trial and error methods.


2017 ◽  
Vol 26 (12) ◽  
pp. 1750196 ◽  
Author(s):  
Yanzhao Ma ◽  
Yinghui Zou ◽  
Shengbing Zhang ◽  
Xiaoya Fan

A fully-integrated self-startup circuit with ultra-low voltage for thermal energy harvesting is presented in this paper. The converter is composed of an enhanced swing LC oscillator and a charge pump with decreased equivalent input capacitance. The LC oscillator has ultra-low input voltage and high output voltage swing, and the charge pump has a fast charging speed and small equivalent input capacitance. This circuit is designed with 0.18[Formula: see text][Formula: see text]m standard CMOS process. The simulation results show that the output voltage is in the range of 0.14[Formula: see text]V and 2.97[Formula: see text]V when the input voltage is changed from 50[Formula: see text]mV to 150[Formula: see text]mV. The output voltage could reach 2.87[Formula: see text]V at the input voltage of 150[Formula: see text]mV and the load of 1[Formula: see text]M[Formula: see text]. The maximum efficiency is in the range of 10.0% and 14.8% when the input voltage is changed from 0.2[Formula: see text]V to 0.4[Formula: see text]V. The circuit is suitable for thermoelectric energy harvesting to start with ultra-low input voltage.


Author(s):  
S. D. Moss ◽  
L. A. Vandewater ◽  
S. C. Galea

This work reports on the modelling and experimental validation of a bi-axial vibration energy harvesting approach that uses a permanent-magnet/ball-bearing arrangement and a wire-coil transducer. The harvester’s behaviour is modelled using a forced Duffing oscillator, and the primary first order steady state resonant solutions are found using the homotopy analysis method (or HAM). Solutions found are shown to compare well with measured bearing displacements and harvested output power, and are used to predict the wideband frequency response of this type of vibration energy harvester. A prototype harvesting arrangement produced a maximum output power of 12.9 mW from a 12 Hz, 500 milli-g (or 4.9 m/s2) rms excitation.


2015 ◽  
Vol 24 (09) ◽  
pp. 1550132 ◽  
Author(s):  
Li-Ye Cheng ◽  
Xin-Quan Lai

A mode-selectable oscillator (OSC) with variable duty cycle for improved charge pump efficiency is proposed in this paper. The novel OSC adjusts its duty cycle according to the operation mode of the charge pump, thus improves the charge-pump efficiency and dynamic performance. The control of variable duty cycle is implemented in digital logic hence it provides robust noise immunity and instantaneous response. The OSC and the charge-pump have been implemented in a 0.6-μm 40-V CMOS process. Experimental results show that the peak efficiency is 92.7% at 200-mA load, the recovery time is less than 25 μs and load transient is 15 mV under 500-mA load variation. The system is able to work under a wide range of input voltage (V IN ) in all modes with low EMI.


2014 ◽  
Vol 1008-1009 ◽  
pp. 49-53
Author(s):  
Si Yuan Ren ◽  
Can Song ◽  
Ying Bo Chen ◽  
Guang Chen Yu

According to the theory of solar energy and vibration energy harvesting, an energy harvesting system based on energy conversion scavenging technology has been designed to convert the solar energy and vibration energy into the electric power. Piezoelectric materials and the solar cells are used as core power conversion section, and the system also consists of the lithium battery charge chip, the rectifier, comparators and switch chips as the control segments, combined with the super capacitor, etc. The energy harvesting experiment shows that the lithium battery can be charged through solar and vibration by the solar and vibration energy harvesting system, and the charging chip adopted in this work has input voltage limited current mode which can fulfill intermittent charge smoothly.


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