The Experts below are selected from a list of 132 Experts worldwide ranked by ideXlab platform
Eugenio Cantatore - One of the best experts on this subject based on the ideXlab platform.
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A 93.3% Peak-Efficiency Self-Resonant Hybrid-Switched-Capacitor Led Driver in 0.18- $\mu$ m CMOS Technology
IEEE Journal of Solid-State Circuits, 2018Co-Authors: Juan C. Castellanos, Mert Turhan, Eugenio CantatoreAbstract:This paper presents an integrated light-emitting diode (Led) driver based on a self-resonant hybrid-switched-capacitor converter (H-SCC) operating in the megahertz range. An integrated zero-current detection (ZCD) circuit is designed to enable self-resonant operation and zero-current switching. A self-resonant timer is proposed to set the switching frequency to resonance automatically, accommodating for variations in the Led Voltage, output current, inductor value, and/or parasitic components, and improving the converter efficiency at light loads without the need for an accurate clock with variable frequency. A ZCD threshold control is also proposed to enable continuous conduction mode and improve efficiency at large currents. The design of high-speed integrated current sensors to measure the inductor current in the H-SCC is also presented. Capacitors, power switches, ZCD, current monitors, and the control circuitry of the Led driver are integrated on-chip in a low-cost, 5-V, 0.18- $\mu \text{m}$ bulk CMOS technology. The proposed driver was measured using inductor values between 36 and 470 nH. It achieves a peak efficiency of 93.3% and an efficiency of 83.1% at the nominal current. The Led driver is able to control a 700-mA Led down to less than 10% of its nominal current. The effective chip area is 7.5 mm2, and the maximum power density is 373 mW/mm2. To our knowLedge, this Led driver can achieve efficiencies comparable to prior art Led drivers using a 6.6 $\times $ smaller inductor.
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ESSCIRC - A 92.2% peak-efficiency self-resonant hybrid switched-capacitor Led driver in 0.18μm CMOS
ESSCIRC 2017 - 43rd IEEE European Solid State Circuits Conference, 2017Co-Authors: Juan C. Castellanos, Mert Turhan, Marcel A. M. Hendrix, Arthur Van Roermund, Eugenio CantatoreAbstract:This paper presents a Led driver IC based on a self-resonant Hybrid-Switched Capacitor Converter (H-SCC) operating in the MHz range. Capacitors and switches of the Led driver are integrated on-chip in a low-cost 5V 0.18μm bulk CMOS technology. The effective chip area is 7.5mm2. A conventional SMD output capacitor and a 6.4 mm2 150nH SMD air-core inductor are enough to operate the driver in a compact PCB area. Integrated zero-current detection (ZCD) circuitry enables self-resonant operation and Zero-Current Switching independently of the output current, inductor tolerances and/or parasitics, improving the converter efficiency at light loads. A ZCD threshold control enables continuous conduction mode too, to improve efficiency at large currents. The experimental results show a peak efficiency of 92.2% and a maximum power density of 373mW/mm2. The Led driver is able to control a 700mA Led down to 10% of its nominal current and can adjust to Led Voltage variations, avoiding the need for Led binning.
Juan C. Castellanos - One of the best experts on this subject based on the ideXlab platform.
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A 93.3% Peak-Efficiency Self-Resonant Hybrid-Switched-Capacitor Led Driver in 0.18- $\mu$ m CMOS Technology
IEEE Journal of Solid-State Circuits, 2018Co-Authors: Juan C. Castellanos, Mert Turhan, Eugenio CantatoreAbstract:This paper presents an integrated light-emitting diode (Led) driver based on a self-resonant hybrid-switched-capacitor converter (H-SCC) operating in the megahertz range. An integrated zero-current detection (ZCD) circuit is designed to enable self-resonant operation and zero-current switching. A self-resonant timer is proposed to set the switching frequency to resonance automatically, accommodating for variations in the Led Voltage, output current, inductor value, and/or parasitic components, and improving the converter efficiency at light loads without the need for an accurate clock with variable frequency. A ZCD threshold control is also proposed to enable continuous conduction mode and improve efficiency at large currents. The design of high-speed integrated current sensors to measure the inductor current in the H-SCC is also presented. Capacitors, power switches, ZCD, current monitors, and the control circuitry of the Led driver are integrated on-chip in a low-cost, 5-V, 0.18- $\mu \text{m}$ bulk CMOS technology. The proposed driver was measured using inductor values between 36 and 470 nH. It achieves a peak efficiency of 93.3% and an efficiency of 83.1% at the nominal current. The Led driver is able to control a 700-mA Led down to less than 10% of its nominal current. The effective chip area is 7.5 mm2, and the maximum power density is 373 mW/mm2. To our knowLedge, this Led driver can achieve efficiencies comparable to prior art Led drivers using a 6.6 $\times $ smaller inductor.
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ESSCIRC - A 92.2% peak-efficiency self-resonant hybrid switched-capacitor Led driver in 0.18μm CMOS
ESSCIRC 2017 - 43rd IEEE European Solid State Circuits Conference, 2017Co-Authors: Juan C. Castellanos, Mert Turhan, Marcel A. M. Hendrix, Arthur Van Roermund, Eugenio CantatoreAbstract:This paper presents a Led driver IC based on a self-resonant Hybrid-Switched Capacitor Converter (H-SCC) operating in the MHz range. Capacitors and switches of the Led driver are integrated on-chip in a low-cost 5V 0.18μm bulk CMOS technology. The effective chip area is 7.5mm2. A conventional SMD output capacitor and a 6.4 mm2 150nH SMD air-core inductor are enough to operate the driver in a compact PCB area. Integrated zero-current detection (ZCD) circuitry enables self-resonant operation and Zero-Current Switching independently of the output current, inductor tolerances and/or parasitics, improving the converter efficiency at light loads. A ZCD threshold control enables continuous conduction mode too, to improve efficiency at large currents. The experimental results show a peak efficiency of 92.2% and a maximum power density of 373mW/mm2. The Led driver is able to control a 700mA Led down to 10% of its nominal current and can adjust to Led Voltage variations, avoiding the need for Led binning.
Isamu Akasaki - One of the best experts on this subject based on the ideXlab platform.
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reduction of contact resistance in v based electrode for high aln molar fraction n type algan by using thin sinx intermediate layer
Physica Status Solidi (c), 2016Co-Authors: Noriaki Nagata, Takashi Senga, Tetsuya Takeuchi, Motoaki Iwaya, Satoshi Kamiyama, Isamu AkasakiAbstract:We found out the reduction of contact resistance in V-based electrode for high AlN molar fraction n-type AlGaN by using thin SiNx intermediate layer. The contact resistivity for n -type Al0.70Ga0.30N with the V/Al/Ni/Au electrode using SiNx intermediated layer reached 1.13 × 10-6 Ω cm2. Moreover, contact resistivity using SiNx intermediated layer had been reduced more than one order of magnitude in all AlN molar fractions from 0.62 to 0.87. Using this electrode, we also demonstrated UV light-emitting diodes (Leds) on n -type Al0.70Ga0.30N underlying layer with an emission wavelength of approximately 283 nm. An operating Led Voltage using a V/Al/Ni/Au electrode with SiNx intermediated layer was 3.3 V lower at 100 mA current injection than that without SiNx intermediated layer. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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Reduction of contact resistance in V‐based electrode for high AlN molar fraction n‐type AlGaN by using thin SiNx intermediate layer
Physica Status Solidi (c), 2016Co-Authors: Noriaki Nagata, Takashi Senga, Tetsuya Takeuchi, Motoaki Iwaya, Satoshi Kamiyama, Isamu AkasakiAbstract:We found out the reduction of contact resistance in V-based electrode for high AlN molar fraction n-type AlGaN by using thin SiNx intermediate layer. The contact resistivity for n -type Al0.70Ga0.30N with the V/Al/Ni/Au electrode using SiNx intermediated layer reached 1.13 × 10-6 Ω cm2. Moreover, contact resistivity using SiNx intermediated layer had been reduced more than one order of magnitude in all AlN molar fractions from 0.62 to 0.87. Using this electrode, we also demonstrated UV light-emitting diodes (Leds) on n -type Al0.70Ga0.30N underlying layer with an emission wavelength of approximately 283 nm. An operating Led Voltage using a V/Al/Ni/Au electrode with SiNx intermediated layer was 3.3 V lower at 100 mA current injection than that without SiNx intermediated layer. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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Reduction of contact resistance in V‐based electrode for high AlN molar fraction n‐type AlGaN by using thin SiNx intermediate layer
Physica Status Solidi (c), 2016Co-Authors: Noriaki Nagata, Takashi Senga, Tetsuya Takeuchi, Motoaki Iwaya, Satoshi Kamiyama, Isamu AkasakiAbstract:We found out the reduction of contact resistance in V-based electrode for high AlN molar fraction n-type AlGaN by using thin SiNx intermediate layer. The contact resistivity for n -type Al0.70Ga0.30N with the V/Al/Ni/Au electrode using SiNx intermediated layer reached 1.13 × 10-6 Ω cm2. Moreover, contact resistivity using SiNx intermediated layer had been reduced more than one order of magnitude in all AlN molar fractions from 0.62 to 0.87. Using this electrode, we also demonstrated UV light-emitting diodes (Leds) on n -type Al0.70Ga0.30N underlying layer with an emission wavelength of approximately 283 nm. An operating Led Voltage using a V/Al/Ni/Au electrode with SiNx intermediated layer was 3.3 V lower at 100 mA current injection than that without SiNx intermediated layer. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Mert Turhan - One of the best experts on this subject based on the ideXlab platform.
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A 93.3% Peak-Efficiency Self-Resonant Hybrid-Switched-Capacitor Led Driver in 0.18- $\mu$ m CMOS Technology
IEEE Journal of Solid-State Circuits, 2018Co-Authors: Juan C. Castellanos, Mert Turhan, Eugenio CantatoreAbstract:This paper presents an integrated light-emitting diode (Led) driver based on a self-resonant hybrid-switched-capacitor converter (H-SCC) operating in the megahertz range. An integrated zero-current detection (ZCD) circuit is designed to enable self-resonant operation and zero-current switching. A self-resonant timer is proposed to set the switching frequency to resonance automatically, accommodating for variations in the Led Voltage, output current, inductor value, and/or parasitic components, and improving the converter efficiency at light loads without the need for an accurate clock with variable frequency. A ZCD threshold control is also proposed to enable continuous conduction mode and improve efficiency at large currents. The design of high-speed integrated current sensors to measure the inductor current in the H-SCC is also presented. Capacitors, power switches, ZCD, current monitors, and the control circuitry of the Led driver are integrated on-chip in a low-cost, 5-V, 0.18- $\mu \text{m}$ bulk CMOS technology. The proposed driver was measured using inductor values between 36 and 470 nH. It achieves a peak efficiency of 93.3% and an efficiency of 83.1% at the nominal current. The Led driver is able to control a 700-mA Led down to less than 10% of its nominal current. The effective chip area is 7.5 mm2, and the maximum power density is 373 mW/mm2. To our knowLedge, this Led driver can achieve efficiencies comparable to prior art Led drivers using a 6.6 $\times $ smaller inductor.
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ESSCIRC - A 92.2% peak-efficiency self-resonant hybrid switched-capacitor Led driver in 0.18μm CMOS
ESSCIRC 2017 - 43rd IEEE European Solid State Circuits Conference, 2017Co-Authors: Juan C. Castellanos, Mert Turhan, Marcel A. M. Hendrix, Arthur Van Roermund, Eugenio CantatoreAbstract:This paper presents a Led driver IC based on a self-resonant Hybrid-Switched Capacitor Converter (H-SCC) operating in the MHz range. Capacitors and switches of the Led driver are integrated on-chip in a low-cost 5V 0.18μm bulk CMOS technology. The effective chip area is 7.5mm2. A conventional SMD output capacitor and a 6.4 mm2 150nH SMD air-core inductor are enough to operate the driver in a compact PCB area. Integrated zero-current detection (ZCD) circuitry enables self-resonant operation and Zero-Current Switching independently of the output current, inductor tolerances and/or parasitics, improving the converter efficiency at light loads. A ZCD threshold control enables continuous conduction mode too, to improve efficiency at large currents. The experimental results show a peak efficiency of 92.2% and a maximum power density of 373mW/mm2. The Led driver is able to control a 700mA Led down to 10% of its nominal current and can adjust to Led Voltage variations, avoiding the need for Led binning.
Hungshiang Chuang - One of the best experts on this subject based on the ideXlab platform.
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single stage power factor correction circuit with flyback converter to drive Leds for lighting applications
IEEE Industry Applications Society Annual Meeting, 2010Co-Authors: Yingchun Chuang, Hungshiang ChuangAbstract:White light emitting diode (Led) with high brightness has attracted a lot of attention from both industry and academia for its high efficiency, ease to drive, environmental friendliness, and long lifespan. They become possible applications to replace the incandescent bulbs and fluorescent lamps in residential, industrial and commercial lighting. The realization of this new lighting source requires both tight Led Voltage regulation and high power factor as well. This paper proposed a single-stage flyback converter for the Led lighting applications and input power factor correction. A type-II compensator has been inserted in the Voltage loop providing sufficient bandwidth and stable phase margin. The flyback converter is controlLed with Voltage mode pulse width modulation (PWM) and run in discontinuous conduction mode (DCM) so that the inductor current follows the rectified input Voltage, resulting in high power factor. A prototype topology of closed-loop, single-stage flyback converter for Led driver circuit designed for an 18W Led lighting source is constructed and tested to verify the theoretical predictions. The measured performance of the Led lighting fixture can achieve a high power factor greater than 0.998 and a low total harmonic distortion less than 5.0%. Experimental results show the functionality of the overall system and prove it to be an effective solution for the new lighting applications.
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IAS - Single-Stage Power-Factor-Correction Circuit with Flyback Converter to Drive Leds for Lighting Applications
2010 IEEE Industry Applications Society Annual Meeting, 2010Co-Authors: Yingchun Chuang, Hungshiang ChuangAbstract:White light emitting diode (Led) with high brightness has attracted a lot of attention from both industry and academia for its high efficiency, ease to drive, environmental friendliness, and long lifespan. They become possible applications to replace the incandescent bulbs and fluorescent lamps in residential, industrial and commercial lighting. The realization of this new lighting source requires both tight Led Voltage regulation and high power factor as well. This paper proposed a single-stage flyback converter for the Led lighting applications and input power factor correction. A type-II compensator has been inserted in the Voltage loop providing sufficient bandwidth and stable phase margin. The flyback converter is controlLed with Voltage mode pulse width modulation (PWM) and run in discontinuous conduction mode (DCM) so that the inductor current follows the rectified input Voltage, resulting in high power factor. A prototype topology of closed-loop, single-stage flyback converter for Led driver circuit designed for an 18W Led lighting source is constructed and tested to verify the theoretical predictions. The measured performance of the Led lighting fixture can achieve a high power factor greater than 0.998 and a low total harmonic distortion less than 5.0%. Experimental results show the functionality of the overall system and prove it to be an effective solution for the new lighting applications.