The Experts below are selected from a list of 82875 Experts worldwide ranked by ideXlab platform
Xiaocheng Jing - One of the best experts on this subject based on the ideXlab platform.
-
a wide load range Constant Charge auto hopping control single inductor dual output boost regulator with minimized cross regulation
IEEE Journal of Solid-state Circuits, 2011Co-Authors: Xiaocheng JingAbstract:A novel single-inductor-dual-output (SIDO) boost regulator with sequential-control is presented. This control can handle large loads or unbalanced loads with minimized cross interference between channels. A Constant-Charge-auto-hopping (CCAH) control is also presented to further extend the power handling capacity of the regulator with a predictable system switching noise spectrum. The switching frequency of the converter can be automatically hopped between 1 MHz and 1 MHz/N where N = 2 to 7 according to the total loads and during load transient. To minimize cross-regulation during frequency hopping, the inductor peak current is set to a predefined value according to the switching frequency information from the frequency detection unit to deliver a Constant Charge per switching period to the unchanged outputs. The response of the transient output is also enhanced with this inductor peak current prediction method. A prototype has been fabricated with a 0.35 μm CMOS process to verify the effectiveness of the CCAH control. With 1.8 V-2.4 V input voltage, two regulated output voltages between 3.0 V and 3.6 V, with maximum 400 mA to 600 mA driving capability and maximum power efficiency of 91.6% is achieved at total output power of 1.15 W. Load transient measurements show that the worst-case cross-regulation is 0.033 mV/mA with a 300 mA load current change at output A and 0.0714 mV/mA with a 280 mA load current change at output B. No noticeable cross-regulation can be observed with a less than 200 mA load current change.
-
a wide load range single inductor dual output boost regulator with minimized cross regulation by Constant Charge auto hopping ccah control
Custom Integrated Circuits Conference, 2009Co-Authors: Xiaocheng JingAbstract:A novel single-inductor-dual-output (SIDO) boost regulator with Constant-Charge-auto-hopping (CCAH) control to minimize the cross interference between channels is presented. In order to have a predictable system switching noise spectrum, the switching frequency of the converter is automatically hopped between 1.25MHz and 1.25MHz/N where N = 2 to 5 according to the loads and during transient. A prototype has been fabricated with a 0.35μm CMOS process to verify the effectiveness of CCAH control. With 1.8V–2.4V input voltage, two regulated output voltages between 3.0V and 3.6V, each with maximum 250mA driving capability, are provided. Load transient measurements show that the cross-regulation is less than 0.1mV/mA with a 200mA change of load current.
-
CICC - A wide-load-range single-inductor-dual-output boost regulator with minimized cross-regulation by Constant-Charge-auto-hopping (CCAH) control
2009 IEEE Custom Integrated Circuits Conference, 2009Co-Authors: Xiaocheng Jing, Philip K. T. Mok, Ming Chak LeeAbstract:A novel single-inductor-dual-output (SIDO) boost regulator with Constant-Charge-auto-hopping (CCAH) control to minimize the cross interference between channels is presented. In order to have a predictable system switching noise spectrum, the switching frequency of the converter is automatically hopped between 1.25MHz and 1.25MHz/N where N = 2 to 5 according to the loads and during transient. A prototype has been fabricated with a 0.35μm CMOS process to verify the effectiveness of CCAH control. With 1.8V–2.4V input voltage, two regulated output voltages between 3.0V and 3.6V, each with maximum 250mA driving capability, are provided. Load transient measurements show that the cross-regulation is less than 0.1mV/mA with a 200mA change of load current.
Orla Feely - One of the best experts on this subject based on the ideXlab platform.
-
Limit on converted power in resonant electrostatic vibration energy harvesters
Applied Physics Letters, 2012Co-Authors: Elena Blokhina, Peter Harte, Dimitri Galayko, Philippe Basset, Orla FeelyAbstract:Based on the formal analysis of a resonant electrostatic vibration energy harvester operating in Constant-Charge mode with a gap-closing transducer, we show that the system displays universal behaviour patterns. In this paper, we treat the harvester as a nonlinear forced oscillator and bound the area of control parameters where the system displays regular harmonic oscillations allowing the conditioning circuit to operate in the most effective mode. Before the system exhibits irregular behaviour, there exists a universal optimal value of normalised converted power regardless of the system design and control parameters.
-
Bifurcation Scenarios in Electrostatic Vibration Energy Harvesters
NDES 2012; Nonlinear Dynamics of Electronic Systems, 2012Co-Authors: Eoghan O'riordan, Peter Harte, Elena Blokhina, Dimitri Galayko, Orla FeelyAbstract:In this paper, we present numerical bifurcation analysis of an electrostatic vibration energy harvester operating in Constant-Charge mode and using the in-plane gap closing transducer. We show how the system can be represented as a nonlinear oscillator and analysed using methods of nonlinear dynamics. We verify previous analytical theories and explain the behaviour of these energy harvesters, particularly in the regime between the first period doubling bifurcation and chaos.
Zhi-pan Liu - One of the best experts on this subject based on the ideXlab platform.
-
Constant-Charge Reaction Theory for Potential-Dependent Reaction Kinetics at the Solid–Liquid Interface
The Journal of Physical Chemistry C, 2014Co-Authors: Ya-hui Fang, Guangfeng Wei, Zhi-pan LiuAbstract:To understand the potential-dependent kinetics of reactions at the solid–liquid interface, we derive a Constant-Charge reaction theory for understanding the coupled Charge transfer during the chemical bond making/breaking. The Charge transfer coefficient (CTC) for reactions at the solid–liquid interface is shown to be linearly proportional to the electrochemical potential change from the initial state to the transition state as well the interface differential capacitance at the Constant-Charge model, and can be further related to the net dipole change normal to the surface during the reaction. Using the Constant-Charge theory, the CTC can be explicitly calculated on the basis of the first principles calculations without the need to assume the redox behavior of the elementary reactions and thus provide a unique possibility to evaluate and compare the magnitude of CTC for different reactions across different surfaces. By examining a series of interface reactions and comparing the calculated CTC values, we p...
-
Constant Charge reaction theory for potential dependent reaction kinetics at the solid liquid interface
Journal of Physical Chemistry C, 2014Co-Authors: Ya-hui Fang, Guangfeng Wei, Zhi-pan LiuAbstract:To understand the potential-dependent kinetics of reactions at the solid–liquid interface, we derive a Constant-Charge reaction theory for understanding the coupled Charge transfer during the chemical bond making/breaking. The Charge transfer coefficient (CTC) for reactions at the solid–liquid interface is shown to be linearly proportional to the electrochemical potential change from the initial state to the transition state as well the interface differential capacitance at the Constant-Charge model, and can be further related to the net dipole change normal to the surface during the reaction. Using the Constant-Charge theory, the CTC can be explicitly calculated on the basis of the first principles calculations without the need to assume the redox behavior of the elementary reactions and thus provide a unique possibility to evaluate and compare the magnitude of CTC for different reactions across different surfaces. By examining a series of interface reactions and comparing the calculated CTC values, we p...
Mathieu Salanne - One of the best experts on this subject based on the ideXlab platform.
-
Simulating Supercapacitors: Can We Model Electrodes As Constant Charge Surfaces?
Journal of Physical Chemistry Letters, 2013Co-Authors: Céline Merlet, Clarisse Péan, Benjamin Rotenberg, Paul A Madden, Patrice Simon, Mathieu SalanneAbstract:Supercapacitors based on an ionic liquid electrolyte and graphite or nanoporous carbon electrodes are simulated using molecular dynamics. We compare a simplified electrode model in which a Constant, uniform Charge is assigned to each carbon atom with a realistic model in which a Constant potential is applied between the electrodes (the carbon Charges are allowed to fluctuate). We show that the simulations performed with the simplified model do not provide a correct description of the properties of the system. First, the structure of the adsorbed electrolyte is partly modified. Second, dramatic differences are observed for the dynamics of the system during transient regimes. In particular, upon application of a Constant applied potential difference, the increase in the temperature, due to the Joule effect, associated with the creation of an electric current across the cell follows Ohm's law, while unphysically high temperatures are rapidly observed when Constant Charges are assigned to each carbon atom.
Elena Blokhina - One of the best experts on this subject based on the ideXlab platform.
-
Limit on converted power in resonant electrostatic vibration energy harvesters
Applied Physics Letters, 2012Co-Authors: Elena Blokhina, Peter Harte, Dimitri Galayko, Philippe Basset, Orla FeelyAbstract:Based on the formal analysis of a resonant electrostatic vibration energy harvester operating in Constant-Charge mode with a gap-closing transducer, we show that the system displays universal behaviour patterns. In this paper, we treat the harvester as a nonlinear forced oscillator and bound the area of control parameters where the system displays regular harmonic oscillations allowing the conditioning circuit to operate in the most effective mode. Before the system exhibits irregular behaviour, there exists a universal optimal value of normalised converted power regardless of the system design and control parameters.
-
Bifurcation Scenarios in Electrostatic Vibration Energy Harvesters
NDES 2012; Nonlinear Dynamics of Electronic Systems, 2012Co-Authors: Eoghan O'riordan, Peter Harte, Elena Blokhina, Dimitri Galayko, Orla FeelyAbstract:In this paper, we present numerical bifurcation analysis of an electrostatic vibration energy harvester operating in Constant-Charge mode and using the in-plane gap closing transducer. We show how the system can be represented as a nonlinear oscillator and analysed using methods of nonlinear dynamics. We verify previous analytical theories and explain the behaviour of these energy harvesters, particularly in the regime between the first period doubling bifurcation and chaos.