一种车用恒流/恒压模式的四开关Buck-Boost变换器控制策略研究

对一种车用恒流/恒压模式的四开关Buck-Boost变换器的控制策略进行了研究。在输入输出电压接近时引入Buck-Boost模式,从而在不同输入输出电压大小关系下,通过检测功率管占空比大小,实现Buck模式、Boost模式和Buck-Boost模式之间的平滑切换,提高了系统的稳定性。通过设计最大值选择电路,使变换器在充电应用中自动从恒流模式切换到恒压模式,模式切换平滑稳定。仿真结果表明,在24 V输出电压下,变换器从Buck模式切换到Buck-Boost模式时,输出电压下冲为9.2 mV,变换器从Boost模式切换到Buck-Boost模式时,输出电压下冲为92 mV。变换器在Buck模式与Boost模式下均能实现恒流/恒压模式的自动平滑切换。     

Buck or boost tracking power converter

A cascade of buck and boost converter is presented here. The control operates in a manner that the converter is either in buck or boost (BOB) mode on a cycle by cycle basis. It transitions between the modes seamlessly to provide a tracking power conversion function for modulating the power supply of a variable envelope radio frequency (RF) power amplifier. The control algorithm and its implementation using switched capacitor circuits is described. Simulation and measured experimental results including converter efficiency, tracking accuracy, and spectrum at the output of the RF power amplifier are provided. This control technique allows seamless transition between the buck and boost modes while tracking RF envelopes with bandwidth greater than 100 kHz, and maintaining extreme accuracy and extremely low ripple. The efficiency of this converter operating at 1.68 MHz is close to 90% over a wide range of conversion ratios. The area of the power converter is extremely small allowing this to be integrated into a cellular telephone. The controller was integrated as part of a larger power management IC as well as a discrete IC.     

A Seamless Mode Transfer Maximum Power Point Tracking Controller For Thermoelectric Generator Applications

A boost-cascaded-with-buck converter-based power conditioning system employing a seamless mode transfer maximum power point tracking controller is proposed to maximize energy production of a thermoelectric generator while balancing a vehicle battery, alternator output power, and vehicle load. When a vehicle battery is fully charged, the proposed controller switches to a power matching mode seamlessly by a dual loop control system, which detects the input and output voltages and currents of the boost-cascaded-with-buck converter, and adjusts the commands accordingly. Both voltage and current loops are designed in a frequency domain using small signal models to ensure stable operation. A mode selection and voltage and current commands are determined by a digital signal processor-based controller. The experimental results with a dynamic source and load steps are presented to show the effectiveness of the proposed approach.      

High efficiency boost converter with variable output voltage using a self-reference comparator

This paper presents a boost converter with variable output voltage and a new maximum power point tracking (MPPT) scheme for biomedical applications. The variable output voltage feature facilitates its usage in a wide range of applications. This is achieved by means of a new low-power self-reference comparator. A new modified MPPT scheme is proposed which improves the efficiency by 10%. Also, to further increase the efficiency, a level converter circuit is used to lower the V_dd of the digital section. The low input voltage requirements allow operation from a thermoelectric generator powered by body heat. Using this approach, a thermoelectric energy harvesting circuit has been designed in a 180 nm CMOS technology. According to HSPICE Simulation results, the circuit operates from input voltages as low as 40 mV and generates output voltages ranging from 1 to 3 V. A maximum power of 138 μW can be obtained from the output of the boost converter which means that the maximum end-to-end efficiency is 52%.     

A UPS With 110-V/220-V Input Voltage and High-Frequency Transformer Isolation

This paper proposes an isolated double-conversion uninterruptible power system with power factor correction using a high-frequency transformer and with input voltages equal to 110 V/220 V. The arrangement is suitable to rack-type structures because it has a small size and a reduced weight. For both input voltages, the proposed converter has almost the same efficiency processing the same output power. Other relevant features include soft commutation of the controlled switches in the chopper and boost stages, a simple control strategy that can be implemented with well-known integrated circuits, and the use of few batteries in series due to the step-up stage. Qualitative analysis and experimental results obtained with a 2-kVA prototype show a normal efficiency of over 86% for the worst case of input voltage and an input power factor of over 99%.      

Transformer‐Reuse Reconfigurable Synchronous Boost Converter with 20 mV MPPT‐Input, 88% Efficiency,and 37 mW Maximum Output Power

This paper presents a transformer‐based reconfigurable synchronous boost converter. The lowest maximum power point tracking (MPPT)‐input voltage and peak efficiency of the proposed boost converter, 20 mV and 88%, respectively, were achieved using a reconfigurable synchronous structure, static power loss minimization design, and efficiency boost mode change (EBMC) method. The proposed reconfigurable synchronous structure for high efficiency enables both a transformer‐based self‐startup mode (TSM) and an inductor‐based MPPT mode (IMM) with a power PMOS switch instead of a diode. In addition, a static power loss minimization design, which was developed to reduce the leakage current of the native switch and quiescent current of the control blocks, enables a low input operation voltage. Furthermore, the proposed EBMC method is able to change the TSM into IMM with no additional time or energy loss. A prototype chip was implemented using a 0.18‐μm CMOS process, and operates within an input voltage range of 9 mV to 1 V, and an output voltage range of 1 V to 3.3 V, and provides a maximum output power of 37 mW.     

高性能PWM型DC-DC升压变换器研究

设计了一种单片集成PWM型电流模式升压变换器,芯片内部集成了耐压22V的DMOS功率开关管,开关频率为1.6MHz,采用1.5μmBCD工艺实现。芯片具有很宽的输入电压(2.7~14V)、高效率(85%)、低关断电流、快速暂态响应和低功耗等特性,适宜于用作便携式设备的电源管理,也可作为IP核,嵌入同种工艺下的其它芯片。文中除了对芯片设计方法、思路及主要电路模块结构的设计方案进行讨论外,还提出了减小单片集成开关电源噪声的措施。     

A single-input dual-output 13.56 MHz CMOS AC–DC converter with comparator-driven rectifiers for implantable devices

A highly efficient single-input, dual-output AC–DC converter for wireless power transfer in implantable devices is implemented using the 0.18-µm CMOS process. The proposed AC–DC converter, consisting of three rectifiers with cross-coupled NMOS transistors and comparator-driven PMOS transistors, achieves up to 79.5% power conversion efficiency at 13.56 MHz operation frequency in order to provide dual outputs of 1.2 V and 2.2 V DC voltages along with 6.2 mA and 22.6 mA of current, respectively, to the implant device from a single RF input. The designed IC consumes a core die area of 0.18 mm².     

一种带自适应斜坡补偿的PCM控制Boost变换器

设计了一种带自适应斜坡补偿的峰值电流模式(PCM)控制Boost变换器。采用一种低功耗自适应斜坡补偿电路,使得升压(Boost)变换器能够实现宽输出范围和高带载能力。在此基础上,提出了一种应用于Boost变换器的电感电流采样电路,该电路实现了高采样速度和高采样精度,且具备全周期的电感电流采样特点。变换器基于SMIC 180 nm BCD CMOS工艺设计。仿真结果表明,该带自适应斜坡补偿的PCM控制Boost变换器输入电压转换范围为2.8 V~5.5 V,输出电压转换范围为4.96 V~36.1 V,最大输出负载电流高达5 A。     

一种恒压输出的DC-DC升压电路设计

针对DC-DC升压器存在效率低,纹波电压较大,输出电压不稳定等问题,文中开发和设计了一种具有恒定输出电压的DC-DC升压转换器的方法。通过升压电路和电压反馈技术,将波动的输入电压变成恒定的直流电压输出。该设计通过将转换器的输出电压与参考电压相比较,两者的差值会产生一个PWM信号控制升压器的通断时间,从而达到恒定电压输出。仿真结果显示,该实验电路能在频率为20 kHz的连续导通模式中工作,产生24 V的恒定输出电压,输出功率为100 W。     

New zero voltage switching DC converter with flying capacitors

A new soft switching converter is presented for medium power applications. Two full-bridge converters are connected in series at high voltage side in order to limit the voltage stress of power switches at V_in/2. Therefore, power metal–oxide–semiconductor field-effect transistors (MOSFETs) with 600 V voltage rating can be adopted for 1200 V input voltage applications. In order to balance two input split capacitor voltages in every switching cycle, two flying capacitors are connected on the AC side of two full-bridge converters. Phase-shift pulse-width modulation (PS-PWM) is adopted to regulate the output voltage. Based on the resonant behaviour by the output capacitance of MOSFETs and the resonant inductance, active MOSFETs can be turned on under zero voltage switching (ZVS) during the transition interval. Thus, the switching losses of power MOSFETs are reduced. Two full-bridge converters are used in the proposed circuit to share load current and reduce the current stress of passive and active components. The circuit analysis and design example of the prototype circuit are provided in detail and the performance of the proposed converter is verified by the experiments.     

降压/升压DC-DC转换器四开关控制方法

便携式电子应用设备常常要求它的系统电压，介于电池充分充电的电压和未充分放电的电压范围之间。比如，对于锂离子电池，当输入为2．8伏到4．2伏时，输出为3．3伏。达到这种要求最佳的解决方法就是高效率、同相的四开关拓扑结构的降压／升压DC-DC转换器，这种方法利用一种控制方案，它可以实现降压、降压／升压、升压三种模式自动并且平稳地转换。经HSPICE仿真，采用Hynix0．5um 5VCMOS工艺，在输入电压2．5～5．5V、输出电压3．3V、频率1MHz时，效率高达95％以上。是输出电压处于电池电压范围内的单节锂离子电池、多节碱性电池或NiMH电池应用的理想选择，解决了在便携式电子设备电源设计过程中所遇到的问题。     

一种单片低功耗电荷泵电源管理电路的设计

基于0.6 μm BiCMOS工艺,设计了一款高精度电荷泵电源管理芯片.该芯片利用2倍压电荷泵电源转换原理,芯片内部集成了具有优异频率响应的振荡器电容,施密特触发器提供内部精准频率,PFM调制提供稳定的输出电压.测试结果表明,芯片输入电压范围为2.7～5.5V,输出电压为5V,电压纹波小于20 mV,内部振荡频率为700 kHz,低功耗模式时电流仅为6.73 μA.     

Frequency tunable low ripple and fast response on-chip DC–DC converter for DVFS

Dynamic voltage and frequency scaling (DVFS) is an efficient method to reduce the power consumption in system on-chip. To support DVFS, multiple supply voltages are generated based on different work load frequencies and currents using on-chip DC–DC voltage converter. In this paper a frequency tunable multiple output voltage switched capacitor based dc–dc converter is presented. An analog to digital converter and phase controller is used in the feedback to change the switching frequency and duty cycle of the converter. An input voltage of 1.8 V is converted to 0.6 and 0.8 V for low and high signal frequency respectively. The proposed 2-phase switched capacitor architecture with gain setting of 1:2 is designed with the 90 nm technology. An output ripple of 45 mV is observed and the maximum transient response time of the converter is 17.3 ns (= 58 MHz).     

A bipolar output voltage pulse transformer boost converter with charge pump assisted shunt regulator for thermoelectric energy harvesting

This system presents an energy harvesting system that generates bipolar output voltage (±1 V) based on a miniature 1:1 turn-ratio pulse transformer boost converter using sub-threshold level input voltage source. A shunt regulator is designed using six-transistor Schmitt-Trigger core to limit the boost converter output voltage. Another power stage, i.e. a fully integrated on-chip single-stage cross-coupled charge pump, then generates 3 V output from the unused extra output power of boost converter, which is shunted otherwise. The increased voltage headroom generated is instrumental for sensor, analog and RF circuits. Charge pump clock frequency is designed to adaptively tracking the input voltage, which is sensed using power-saving time-domain digital technique. Based on a standard CMOS 0.13-µm technology, chip measurement verified the operations of the boost converter, shunt regulator and bipolar charge pump prototypes, respectively. Simulations confirmed the full system operations. During start-up, the system only requires minimum start-up input voltage of 36 mV at input power of 5.8 µW.     

Single-stage three-phase buck-boost type AC-DC converter with highpower factor

A new control process for single-stage three-phase buck-boost type AC-DC power converters with high power factor, sinusoidal input currents and adjustable output voltage is proposed. This converter allows variable power factor operation, but this work focus on achieving unity power factor. The proposed control method includes a fast and robust input current controller based on a vectorial sliding mode approach. The active nonlinear control strategy applied to this power converter, allows high quality input currents. Given the comparatively slow dynamics of the DC output voltage, a proportional integral (PI) controller is adopted to regulate the converter output voltage. The voltage controller modulates the amplitudes of the current references, which are sinusoidal and synchronous with the input source voltages. Experimental results from a laboratory prototype show the high power factor and the low harmonic distortion characteristics of the circuit     

一种数字COT控制Buck变换器设计

设计了一种基于数字COT控制的DC-DC变换器。通过分时复用的方法,采用单个ADC实现输入/输出电压和误差电压的量化,并通过内部数字信号计算得到电感电流信息。为克服ADC量程和精度之间的矛盾,使用PGA和DAC实现对6 bit ADC量程的扩展。Buck变换器在输入电压3.3 V、输出电压1.8 V、开关频率1 MHz下进行了仿真验证,输入电压阶跃响应时间从276μs/324μs下降到几乎无影响,负载阶跃响应时间达到39μs/39μs,电源调整率为0.14%,负载调整率为0.14%,输出精度达到了4 mV。     

A low voltage, dynamic, noninverting, synchronous buck-boost converter for portable applications

With the increasing use of low voltage portable devices and growing requirements of functionalities embedded into such devices, efficient power management techniques are needed for longer battery life. Given the highly variable nature of batteries (e.g., 2.7-4.2 V for Li-ion), systems often require supply voltages to be both higher and lower than the battery voltage (e.g., power amplifier for CDMA applications), while supplying significant current, which is most efficiently generated by a noninverting buck-boost switching converter. In this paper, the design and experimental results of a new dynamic, noninverting, synchronous buck-boost converter for low voltage, portable applications is reported. The converter's output voltage is dynamically adjustable (on-the-fly) from 0.4 to 4.0 V, while capable of supplying a maximum load current of 0.65 A from an input supply of 2.4-3.4 V. The worst-case response time of the converter for a 0.4 to 4 V step change in its output voltage (corresponding to a 0.2 to 2 V step at its reference input) is less than 300 /spl mu/sec and to a load-current step of 0 to 0.5 A is within 200 /spl mu/sec, yielding only a transient error of 40 mV in the output voltage. This paper also presents a nonmathematical, intuitive analysis of the time-averaged, small-signal model of a noninverting buck-boost converter.     

A boost DC-AC converter: analysis, design, and experimentation

This paper proposes a new voltage source inverter (VSI) referred to as a boost inverter or boost DC-AC converter. The main attribute of the new inverter topology is the fact that it generates an AC output voltage larger than the DC input one, depending on the instantaneous duty cycle. This property is not found in the classical VSI, which produces an AC output instantaneous voltage always lower than the DC input one. For the purpose of optimizing the boost inverter dynamics, while ensuring correct operation in any working condition, a sliding mode controller is proposed. The main advantage of the sliding mode control over the classical control schemes is its robustness for plant parameter variations, which leads to invariant dynamics and steady-state response in the ideal case. Operation, analysis, control strategy, and experimental results are included in this paper. The new inverter is intended to be used in uninterruptible power supply (UPS) and AC driver systems design whenever an AC voltage larger than the DC link voltage is needed, with no need of a second power conversion stage     

An 80-V integrated boost converter for piezoelectric actuators in smartphones

A boost converter for piezoelectric actuator driving system in haptic smartphones is proposed and implemented using a 0.35 μm BCDMOS process. The designed boost converter generates extremely high output voltage from a low-voltage battery supply. The boost converter provides stable power for the piezoelectric actuator with the peak-current control technique. The minimum variation of the output ripple variation can be achieved by the designed current-sensing and peak-current control circuits. The supply voltage of the boost converter is 2.7–4.2 V and the maximum output voltage is up to 80 V. The complete piezoelectric actuator driving system consists of a serial interface, SRAM, and signal-shaping logic as well as the boost converter. It also includes the resistor-string digital-to-analog converter and high voltage piezoelectric actuator driver (PZ driver). The fabricated chip size is 2,100 × 2,200 μm, including bonding pads.