| 1. |
- Katic, Janko, 1986-, et al.
(författare)
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A Dual-Output Thermoelectric Energy Harvesting Interface with 86.6% Peak Efficiency at 30 μW and Total Control Power of 160 nW
- 2016
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Ingår i: IEEE Journal of Solid-State Circuits. - : IEEE Solid-State Circuits Society. - 0018-9200 .- 1558-173X.
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Tidskriftsartikel (refereegranskat)abstract
- A thermoelectric energy harvesting interface based on a single-inductor dual-output (SIDO) boost converter is presented. A system-level design methodology combined with ultra-low power circuit techniques reduce the power consumption and minimize the losses within the converter. Additionally, accurate zero-current switching (ZCS) and zero-voltage switching (ZVS) techniques are employed in the control circuit to ensure high conversion efficiency at μW input power levels. The proposed SIDO boost converter is implemented in a 0.18 μm CMOS process and can operate from input voltages as low as 15 mV. The measurement results show that the converter achieves a peak conversion efficiency of 86.6% at 30 μW input power.
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| 2. |
- Katic, Janko, 1986-, et al.
(författare)
-
A High-Efficiency Energy Harvesting Interface for Implanted Biofuel Cell and Thermal Harvesters
- 2017
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Ingår i: IEEE transactions on power electronics. - : IEEE Press. - 0885-8993 .- 1941-0107. ; 33:5, s. 4125-4134
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Tidskriftsartikel (refereegranskat)abstract
- A dual-source energy harvesting interface that combines energy from implanted glucose biofuel cell and thermoelectric generator is presented. A single-inductor dual-input dual-output boost converter topology is employed to efficiently transfer the extracted power to the output. A dual-input feature enables the simultaneous maximum power extraction from two harvesters, while a dual-output allows a control circuit to perform complex digital functions at nW power levels. The control circuit reconfigures the converter to improve the efficiency and achieve zero-current and zero-voltage switching. The measurement results of the proposed boost converter, implemented in a 0.18 μm CMOS process, show a peak efficiency of 89.5% when both sources provide a combined input power of 66 μW. In the single-source mode, the converter achieves a peak efficiency of 85.2% at 23 μW for the thermoelectric source and 90.4% at 29 μW for the glucose biofuel cell. The converter can operate from minimum input voltages of 10 mV for the thermoelectric source and 30 mV for the glucose biofuel cell.
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| 3. |
- Katic, Janko, 1986-, et al.
(författare)
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An Adaptive FET Sizing Technique for HighEfficiency Thermoelectric Harvesters
- 2016
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Ingår i: 2016 IEEE International Conference on Electronics, Circuits and Systems (ICECS). - Monte Carlo : IEEE. - 9781509061136 ; , s. 504-507
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Konferensbidrag (refereegranskat)abstract
- A theoretical analysis of losses in low power thermoelectric harvester interfaces is used to find expressions for properly sizing the power transistors according to the input voltage level. These expressions are used to propose an adaptive FET sizing technique that tracks the input voltage level and automatically reconfigures the converter in order to improve its conversion efficiency. The performance of a low-power thermoelectric energy harvesting interface with and without the proposed technique is evaluated by circuit simulations under different input voltage/power conditions. The simulation results show that the proposed technique improves the conversion efficiency of the energy harvesting interface up to 12% at the lowest input voltage/power levels.
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| 4. |
- Katic, Janko, 1986-, et al.
(författare)
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An Efficient Boost Converter Control for Thermoelectric Energy Harvesting
- 2013
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Ingår i: Electronics, Circuits, and Systems (ICECS), 2013 IEEE 20th International Conference on. - : IEEE conference proceedings. ; , s. 385-388
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Konferensbidrag (refereegranskat)abstract
- This paper presents an ultra-low power controlcircuit for a DC-DC boost converter targeting implantablethermoelectric energy harvesting applications. Efficiency of theinput converter is enhanced by utilizing zero-current switchingtechnique. Adaptive delay between ON states of switches assureszero-voltage switching of synchronous rectifier and reducesswitching losses. The control circuit employing both techniquesconsumes an average power of 620nW. This allows the converterto operate from harvested power below 5μW. For voltageconversion ratios above 20, the proposed circuits and techniquesdemonstrate efficiency improvement compared to the state-of-the-art solutions.
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| 5. |
- Katic, Janko, 1986-
(författare)
-
Highly-Efficient Energy Harvesting Interfaces for Implantable Biosensors
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Energy harvesting is identified as an alternative solution for powering implantable biosensors. It can potentially enable the development of self-powered implants if the harvested energy is properly handled. This development implies that batteries, which impose many limitations, are replaced by miniature harvesting devices. Customized interface circuits are necessary to correct for differences in the voltage and power levels provided by harvesting devices from one side, and required by biosensor circuits from another. This thesis investigates the available harvesting sources within the human body, proposes various methods and techniques for designing power-efficient interfaces, and presents two CMOS implementations of such interfaces.Based on the investigation of suitable sources, this thesis focuses on glucose biofuel cells and thermoelectric harvesters, which provide appropriate performance in terms of power density and lifetime. In order to maximize the efficiency of the power transfer, this thesis undertakes the following steps. First, it performs a detailed analysis of all potential losses within the converter. Second, in relation to the performed analysis, it proposes a design methodology that aims to minimize the sum of losses and the power consumption of the control circuit. Finally, it presents multiple design techniques to further improve the overall efficiency.The combination of the proposed methods and techniques are validated by two highly efficient energy harvesting interfaces. The first implementation, a thermoelectric energy harvesting interface, is based on a single-inductor dual-output boost converter. The measurement results show that it achieves a peak efficiency of 86.6% at 30 μW. The second implementation combines the energy from two sources, glucose biofuel cell and thermoelectric harvester, to accomplish reliable multi-source harvesting. The measurements show that it achieves a peak efficiency of 89.5% when the combined input power is 66 μW.
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