2.4 GHz 대역 무선전력전송 고효율 수신부 IC 설계

Wide input or output voltage range converters are required in various applications, including railway, industrial, military, aerospace, and many more. However, it has been challenging to achieve and maintain high efficiency under a wide range of input or output voltages of operation because of shifting operating conditions and compromised component selections required to cover a wide voltage range of operation. In this paper, a method of reconfiguring the flying capacitor multilevel power conversion input stage is revealed for a wide voltage range of operation. The power conversion input stage can be configured to achieve relatively constant voltage stress across key components, namely power switches, inductors, and capacitors, so that components can be selected and optimized for very confined operating conditions. Also, the amplitude and frequency of the pulse voltage at the converter's switching node are also maintained relatively constant. Therefore, a followed filter stage, a resonant tank, or an isolation + rectifier stage can be designed and operated with optimization. High and maintained overall efficiency are achieved over a wide change of the input voltage.

A hybrid control scheme of a regulated multi-modes charge pump and its modeling are proposed in this paper. It can achieve very high efficiency over wide input and load range. It is controlled to adaptively change the conversion mode at different input voltage. It also combines device segmentation and pulse skipping modulation to improve the efficiency over a wide load range. Due to the complexity of its hybrid control scheme, the modeling of multi-modes charge pump is analyzed in order to provide a guide for the compensator design and ensure the stability of system over wide input and load range. Both of the simulation and test results are provided to verify proposed control scheme.

This paper presents a reconfigurable switched-capacitor (SC) DC-DC regulator to simultaneously generate two different regulated output voltages for low-power applications. With capacitor and power switch sharing in the power stage, the area efficiency of the proposed regulator is improved. The proposed power stage can also be configured to provide different conversion ratios in order to maintain high power efficiency of the regulator in different input voltages. A sub-harmonic adaptive-on-time (SHAOT) control scheme is developed to regulate both outputs. The adaptive-on-time control automatically adjusts the durations of charge transfer to both outputs to reduce output voltage ripples under different input voltages. Switching power transistors at the fundamental or sub-harmonics of the system clock frequency can provide predictable noise spectrum to both regulated outputs and improve the light-load regulator power efficiency. The cross regulation between both outputs can also be minimized by the proposed SHAOT scheme. Implemented in a standard 0.35 μm CMOS process, the proposed regulator provides two regulated outputs of 2 V and 3 V and delivers up to 12 mA at each output. The proposed regulator achieves a maximum power efficiency of 89.5%. Both power efficiency and output ripple can be improved by 10% and ~ 4 times, respectively, over a wide input range from 1.1 V to 1.8 V by using the proposed reconfigurable power stage and adaptive-on-time scheme.

Pulse loads, like solid-state pulse modulators, generate short pulses with a high peak power that exceeds the average power by 100-1000 times depending on the pulse repetition rate. There, the peak power usually is drawn from an energy buffer such as a capacitor bank. The pulse discharges the energy buffer, and it is fully recharged in the time between the pulses by a power supply, which is usually connected to the mains. Due to the worldwide variation in mains voltages and the desired ability to adapt to the capacitor voltage of the modulator, the power supply has to support a wide input and output voltage range. Additionally, the supply should draw a sinusoidal current from the mains while providing energy to the pulse modulator due to electromagnetic interference regulations. Therefore, a general control concept for pulse load applications, which guarantees continuous power consumption from the mains and power factor correction, is described in this paper. Furthermore, measurements of the control principle, which is independent from the converter topology, are presented for a three-phase buck-boost rectifier.

A new class of hybrid soft-switching dc-dc converters combining a half-bridge LLC converter and a full-bridge phase-shift modulated converter is proposed for electric vehicle (EV) on-board charger applications. The hybridization allows the converter operating under soft-switching condition in a wide input and output voltage range and from true zero to full load condition. It not only eliminates possible MOSFET damage due to hard-switching under high-voltage low-current condition, but also minimizes the duty cycle loss and circulating current induced conduction loss. The entire on-board charger consists of a power factor correction (PFC) stage and a hybrid dc-dc converter. Both conventional boost and bridgeless PFC converters were implemented to incorporate the proposed hybrid dc-dc converter for a 6.6 kW on-board charger. Hardware prototypes have been designed, fabricated and tested to verify the validity and performance of the proposed circuit. Experimental results show that the proposed topology is attractive for EV onboard charger applications as the design has demonstrated a peak efficiency of 98.4% for the dc-dc stage and 96.1% for the entire on-board charger. The prototype on-board charger has been installed in an EV for field testing.

DC-DC converters are used to convert and regulate voltages depending on the requirement of the specific load. There are two types of DC-DC converter: (1) linear regulators and (2) switching regulators. A linear regulator has a small output voltage ripple but its power efficiency degrades when the difference between the input voltage and output voltage increases. On the other hand, the switching regulator has better power efficiency compared to the linear regulator. The switching regulator can convert wide range of input voltages while maintaining high power efficiency and it can also step-up voltages which a linear regulator cannot. The drawback for switching regulator is the need for control circuit that controls the switches and regulation. The switching regulator has also the problem of relatively larger output voltage ripple, which is not suitable for sensitive circuits. In this paper, a hybrid topology was proposed to combine the advantages of the two DC-DC converters. From the simulation of the three converters, the linear regulator only has an efficiency of 28.058% while the switching regulator and hybrid power converter have efficiencies of 49.0881% and 45.6753%, respectively. In addition, input voltages from 0.5V to 5V were tested on the three regulators that would result in a regulated output voltage of 1V. The linear regulator can only regulate voltages above 1V and the PMOS transistor used has a operating voltage of 2.5V which limits the upper voltage boundary of the linear regulator to 3.5V. The switching regulator can regulate wider range of input voltages but due to power loss across the converter, the switching regulator cannot produce a constant output voltage of 1V when the input voltage ranges from 0.5V to 0.7V. The three converters were designed and implemented in a 65nm CMOS process.

A soft-switching DC-DC converter with secondary-side phase-shift control strategy is proposed for applications requiring wide voltage range and isolated step-down power conversion such as battery charger. Two transformers and a three-leg hybrid rectifier (one MOSFET-leg and two diode-legs) are employed. The primary windings of the two transformers are in-series and the secondary windings are in parallel. Zero voltage switching is achieved for both the primary- and secondary-side power MOSFETs while zero current switching is achieved for the secondary-side diodes in a wide load range. Leakage inductance of the transformers is utilized for power transferring. The voltage stresses of all the devices are clamped automatically. Besides, the converter can operates in the buck, balance and boost modes to achieve a relatively wide input or output voltage range. The secondary-side rectifier can be extended to multiple transformers configuration for high step-down applications. The operation principles are analyzed and experimental results of a 1-kW 100-kHz prototype are provided to verify the effectiveness of the proposed converter.

After demonstrating, in previous works, the proof of concept of adaptive rectifiers with active load modulation to operate simultaneously for short/long range RF Wireless Power Transfer (WPT) while maintaining a high Power Conversion Efficiency (PCE), the authors introduced in this paper a power link budget of the proposed adaptive rectifier with a compromise between distance and efficiency. Then, to further exhibit its capabilities and enhance its performance, this paper first introduced a discussion about the parameters preventing the rectifier from operating over a wide range of input powers was performed. Furthermore, active load modulation was implemented and its co-simulation results presented. Finally, an adaptive rectifier was fabricated and its results successfully compared to measured data. It exhibits 40% of PCE over a wide dynamic input range of incident RF power levels from −6 to 25 dBm at the 900 MHz in the Industrial Scientific Medical band (ISM band), with a maximum PCE of 66% for an input power of 15 dBm. The proposed devices are therefore suitable for WPT applications to harvest energy from a controlled source.

As compared with parallel converters employing buck converters or boost converters, the analysis of multiple-input parallel switched-capacitor (SC) DC-DC converters is not sufficient. In this paper, a multiple-input parallel DC-DC converter designed by using SC techniques is proposed for mobile back-lighting applications, and handy theoretical formulas are given concerning the power efficiency and equivalent circuit. The proposed parallel converter consists of two different kinds of converter blocks: 1. a 1.5× step-up SC DC-DC converter employing an input voltage from a lithium battery and 2. a novel step-up converter employing an input voltage from solar cells. The proposed converter can offer the output voltage for display back-lighting from solar energy, because the proposed step-up converter can achieve not only a large step-up conversion ratio but also a wide input range. Hence, the proposed converter will enable us to realize a long battery life, reduction of heat, and so on. Furthermore, derived theoretical formulas will be helpful to estimate circuit characteristics, because theoretical results agree well with SPICE simulation results. The validity of circuit design is confirmed by simulations and experiments.

The G/sub m/-C technique is extensively used for continuous-time filtering applications because it results in tunable, wideband and compact designs. In this paper, an OTA capable of operating at a supply voltage of 0.9 V is proposed using a novel bulk-input differential pair without the use of a tail current source. Good CMRR (63 dB) is still achieved by using the gate terminal to control the total current in the differential pair, via the use of a dummy pair. The OTA also exhibits a wide differential input range of /spl plusmn/ 600 mV and good G/sub m/- tunability. Simulation and test results are also presented with the OTA used in a second order cochlea low-pass filter. For this design, a standard double-poly double-metal CMOS process has been used, having a nominal threshold voltage of around 0.7 V.

Currently, more decoupled photovoltaic (PV) systems demonstrate significant advantages in terms of efficiency increasing the competitiveness of the produced energy. This trend has been performed specifically in string and multistring configurations, where DC-DC converters are used to perform more distributed maximum power point tracking (MPPT). However, high variability in PV sources requires wide input voltage range capacity for the DC-DC converter affecting the efficiency of a classical DC-DC converter topology. Serial partial power converters (S-PPC) have drawn the attention in the last years due to its high efficiency processing only a fraction of the total power. In this paper it is proposed a two-stage approach for high efficiency step-up/down performance for a partial power conversion. Compared with the Type 1 or Type 2 step-up/down S-PPC, the proposed converter can operates with wider range of operation and presents higher partiality over the full operating range, leading to a higher global efficiency. Simulations are provided to verify the validity of the proposed two stage approach.

This paper proposes a novel high voltage-gain LLC micro-converter for PV applications. The converter has simple structure and minimum components with low cost. It can realize high voltage gain based on the voltage doubler rectifier with the optimal turns ratio. The main power switches can achieve ZVS and the output diodes can realize ZCS in wide input and load range. By utilizing the voltage doubler in the secondary side, the voltage stress over the output diodes can be reduced by half compared to the conventional center-tapped full-wave rectifier. A 24-48 V input, 380 V output and 200W prototype was built to verify the benefits of the proposed converter. The achieved efficiency of the converter peaks at 96.6% and the CEC weighted efficiency reaches 95.4%.

A fully integrated switched-capacitor DC-DC power converter that converts input voltages up to 42 V into 3 V is presented. The converter achieves a wide input operating range with multiple VCRs based on stacking of several isolated switched-capacitor converters. Stacking simplifies the design to a low voltage unit converter with only a few VCRs, while the wide input range high voltage converter achieves the efficiency of the unit converter. The DC-DC converter is designed in a 0.35 µm CMOS technology and achieves an output power of 2.1 mW.

An improved converter for low power and wide range input voltage, which is particularly suitable for auxiliary uses in three-phase grid of industrial applications, is studied. A flyback quasi-resonant topology has been chosen, which offers the good characteristics of high voltage operations and good efficiency. A comparison is performed among available kinds of semiconductor devices with good peculiarities for the specific topic. In particular the analysis focuses on MOSFET and cascode devices. The latter component shows good characteristics in this specific application of high voltage operations at high switching frequency and low power. The converter design is described with a particular attention to the crucial instances of switching and conduction losses and the thermal dissipation. Moreover the quasi-resonant operation mode has been exploited in order to improve the effectiveness of the solution adopted. The zero voltage operation is obtained by a gate driver chip specifically designed to build offline quasi-resonant zero voltage switching in flyback converters. Finally, several experimental tests are considered and specifically described

This paper proposes a new variable-mode control strategy that is applicable for LLC resonant converters operating in a wide input voltage range. This control strategy incorporates advantages from full-bridge LLC resonant converters, half-bridge LLC resonant converters, variable-frequency control mode, and phase-shift control mode. Under this control strategy, different input voltages determine the different operating modes of the circuit. When the input voltage is very low, it works in a full-bridge circuit and variable frequency mode (FB_VF mode). When the input voltage rises to a certain level, it shifts to a full-bridge circuit and phase-shifting control mode (FB_PS mode). When the input voltage further increases, it shifts into a half-bridge circuit and variable frequency mode (HB_VF mode). Such shifts are enabled by the digital signal processor (DSP), which means that no auxiliary circuit is needed, just a modification of the software. From light load to heavy load, the primary MOSFET for the LLC resonant converter can realize zero-voltage switching (ZVS), and the secondary rectifier diode can realize zero-current switching (ZCS). With an LLC resonant converter prototype with a 300 W rated power and a 450 V output voltage, as well as a resonant converter with 20–120 V input voltage, the experiments verified the proposed control strategy. Experimental results showed that under this control strategy, the maximum converter efficiency reaches 95.7% and the range of the input voltage expands threefold.