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The realization of wide input voltage and high power density on the conventional current resonant converter such as LLC converter remarkably increases transformer winding loss and its design difficulty. Therefore, it is difficult for the conventional LLC converter to satisfy both requirements. In order to apply the LLC converter with both conditions, this paper investigates the mechanism of the transformer...
A current resonant converter including wider input voltage range and higher power density is required for various applications. However, in our study, it has been found that the drastic increasing of the transformer winding loss becomes a severe problem. This paper clarifies the mechanism of transformer winding loss occurrence and proposes the different resonant mode operation which solves the problem...
A general-purpose clocked gate driver integrated circuit (IC) to generate an arbitrary gate waveform is proposed to provide a universal platform for fine-grained gate waveform optimization handling various power transistors. The fabricated IC with a 0.18 μm Bipolar-CMOS-DMOS process has 63 P-type MOS (PMOS) and 63 N-type MOS (NMOS) driver transistors on a chip whose activation patterns are controlled...
This paper describes electrical characteristics of a silicon based multi-tens MHz gate driver IC for GaN power devices. The fabricated gate driver IC can operate 50 MHz and drive the GaN power device when sine wave inputs. We fabricated prototype synchronous back converter using GaN power devices and the fabricated driver IC. The fabricated buck converter can operate at 30 MHz and results show that...
Output-inductor-less full-bridge converter for a High-Voltage Direct-Current power distribution system has been proposed. This proposed circuit topology suppresses the surge voltage due to the secondary-side diode's recovery, and miniaturizes the converter because the number of circuit components is reduced. On the other hand, some problems occur, such as the increasing switching-loss of primary switches...
In this paper, a high power-density output-inductor-less full-bridge converter for the HVDC power distribution system is proposed. The new reduction techniques of switching loss and noise in the output-inductor-less full-bridge converter by using SiC-MOSFETs are applied. As the result, the power loss is reduced by 20W in a wide load range, and the noise is also reduced. Furthermore, a high power density...
A general-purpose clocked gate driver (CGD) IC to generate an arbitrary gate waveform is proposed to provide a universal platform for fine-grained gate waveform optimization handling various power transistors. The fabricated IC with 0.18µm BCD process has 63 PMOS and 63 NMOS driver transistors on a chip whose activation patterns are controlled by 6-bit digital signals and 25-MHz clock (= 40-ns time...
This paper proposes a power-loss reduction technique for a kW-scale isolated dc-dc converter, which installs a novel PWM control to achieve the soft-switching of primary side MOS-FETs. As a result, the efficiency is achieved over 90% in a wide load range. Moreover, the temperature of the primary side MOS-FETs can be reduced by 30 degrees when compared with the conventional method, and the power-density...
This paper proposes an isolated DC-DC converter for Power-Supply on chip (SoC) realized by the couple of air-core coils. The pro-posed isolated DC-DC converter is evaluated by numerical simulations and experimental results. The fabricated prototype DC-DC converter works well and the simulation results are good agreement with experimental results. This paper also discusses the potential of proposed...
We propose a multi input voltage and multiple output voltage DC-DC converter using H-bridge converter for power supply on chip. We analyzed the operation mode of the H-bridge converter and also propose the suitable operation mode for power supply on chip. The proposed POLs realize stable output voltage and high efficiency over the wide range through digital control.
This paper proposes a PFM+PWM hybrid controlled soft-switching half-bridge converter which has both benefit of conventional half-bridge converter and LLC converter. Generally, conventional half-bridge converter has good constant current characteristic due to PWM control, however it has some drawbacks of (1) primary side switches and secondary side diodes operate under hard switching, (2) two magnetic...
In this paper, we propose a concept of Field Programmable Power supply Array (FPPA), which is a fully digital controlled power supply, based on power supply on chip technology. The FPPA realize multi input voltage and multi output voltage only rewrite digital code of FPGA or DSP.
A power supply on chip (SoC) has been attracted attentions of many researchers because it can realize ultimate minimization of the power supply. It is quite promising for ICT applications because its features, such as smaller volume, high frequency response, and so on, fit for requirement of POL used in ICT equipment. In this paper, we propose the novel concept of digitally controlled multiple output...
This paper proposes the simple and seamless operation technique for bi-directional LLC resonant converter. Generally, bi-directional operation of LLC resonant converter is complicated and difficult to control. Because, the switching frequency has to be changed across fsr (series resonant frequency) and the switching sequences (the switching timing between high voltage side and low voltage side) has...
A high-voltage full bridge dc-dc converter has a big problem of high-voltage surge occurrence across secondary-side rectifying diodes. In order to solve this problem, a simple solution with a snubber capacitor has been proposed. This technique provides a prominent effect of surge-voltage suppression. On the other hand, it deteriorates the control characteristics of this converter. In this paper, the...
In this study, integrated H-bridge converter with the Matrix-POL power supply system is proposed. From the simulation results, the validity of the Matrix-POL is revealed. The results revealed that the fast response to the load current and the voltage change can be done with duty and parallel number control by the proposed system.
This paper presents the novel load regulation technique for parallel connected POLs which reads for power supply on chip (power-SoC). In power-SoC, many POLs are implemented on the same chip. In this case, the conventional loop control (feedback control) may have some problem such as oscillation. The proposed strategy regulates the output voltage by changing number of the working POLs under fixed...
This paper proposes the new LLC converter with unique control method. Generally, LLC resonant converter, which is controlled by PFM, has the drawback of (1) difficulty of PWM controllability, (2) difficulty of constant current limitation, and (3) narrow input voltage range limitation. These difficulties come from the resonant operation. In order to overcome those drawbacks, a hybrid control of PFM...
This paper proposes the simple and seamless operation technique for bi-directional LLC converter. Generally, bi-directional operation of LLC converter is complicated and difficult to control. Because, the switching frequency has to be changed across fsr (series resonant frequency) and the switching sequences has to be also changed due to resonant characteristics. In order to simplify the switching...
In this study, integrated buck-boost converter with the Matrix-POL power supply system is proposed. From the simulation results, the validity of the Matrix-POL is revealed. The results revealed that the fast response to the load current and the voltage change can be done with duty and parallel number control by the proposed system.
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