用于高侧开关的短路限流及保护电路

提出了一种用于高侧开关的短路限流及保护电路。电路采用二级保护的方式,当短路检测电压不为零且低于参考电压时,限制栅源电压,对电路限流;当短路检测电压高于参考电压时,则延时一段时间后关断功率管。芯片采用0.18μm 100 V BCD工艺流片。测试结果表明,在先工作后短路和先短路后工作两种情况下,功率管均处于正常工作状态。电路工作电压范围为4～80 V,短路延时时间约200μs,输出最大可持续电流可达80 A。     

D类音频功放过流保护电路的设计

本文设计了一种D类音频功放的过流保护电路。通过和功率管同类型,缩小尺寸的采样管监测流过功率管电流的大小,因此在高侧功率管和低侧功率管过流时,使用一个基准电压值和一个比较器就可以完成过流检测及保护功能,有效降低了过流保护电路的功耗和版图面积。栅驱动电路通过一个自举电容不仅为高侧功率管及采样管的开启提供足够的驱动电压,还为过流保护电路提供选择控制信号,交替检测高低侧功率管的过流情况。过流保护电路采用耐高压结构,保证D类音频功放大功率输出时正常工作。     

一种NPN型功率管驱动电路的设计

为NPN型功率管的降压型开关电源芯片设计了一种驱动电路。针对功率管工作在导通状态下的导通损耗和在开关状态转换中的开关损耗,设计了自举电路,使功率管饱和;设计了加速电路,缩短了功率管状态转换所用时间,降低了功率管损耗。在2 μm双极型工艺下进行仿真,结果显示,功率管工作在饱和区,导通损耗小,开关转换速度快,可满足高开关频率的要求。     

发挥功放潜力的减流式保护电路

本文介绍的短路保护电路具有减流特性。由于短路时功率管过流时间只是传统限流式的10~(-6)分之一,可大大拓宽功率管的二次击穿区,使放大器在加有保护电路时仍有充分的功率输出。     

一种新型集成荧光灯电子镇流器用过流保护电路

针对集成荧光灯电子镇流器中存在两个功率开关管直接短路的危害,提出了一种逐时钟周期方式的过流保护电路.与采用逐开关周期的传统过流保护电路相比,它具有更高的可靠性.文章阐述了过流产生的原因及采用本文所提出的过流保护电路的优越性,并仔细分析了电路的工作原理.最后,利用Cadence软件,给出了与理论分析相一致的实际电路的模拟结果.     

半桥式功率输出级中高速低功耗低侧管的实现

本文提出了一种动态地控制IGBT阳极短路的结构,并把这种结构用于具有高低侧驱动和半桥式功率输出级的功率集成电路低侧管中.这种结构使得功率输出级低侧管导通时工作于IGBT模式,关断过程中工作于MOS模式,因而具有导通压降小、关断速度快的优点,有效地解决了功率管导通电阻和关断速度之间的矛盾.在不改变工艺,不降低耐压,不增加电路元件的前提下,实现了低侧管的高速低功耗.     

一种用于功率MOSFET的分段驱动电路设计

为减弱栅极电压过冲振荡,避免功率管在导通和关断过程中对系统以及其他电路产生的电磁干扰,提出了一种新型功率管驱动电路。该电路通过逻辑信号的分段控制,使得被驱动功率管缓慢开启和关断,研究了传统功率驱动电路的模型与工作过程,分析了功率管导通损耗的来源,提出驱动电路的要求,详细阐述了所设计的驱动电路的工作原理与工作过程,整个驱动电路采用0.18μｍ工艺在平台Cadence Spectre仿真并通过PCB板测量实现。理论与仿真结果表明,该设计可以有效达到减弱功率管过冲与振荡的要求,保证系统的稳定。     

基于简单拓扑的单相交流降压变换器研究

分析了一种新型单相交流降压变换器AC_Buck,该变换器由简单的DC-DC电路Buck衍化而来,仅使用两个功率开关,结构简单,控制简便,可实现交流-交流直接降压变换。文中对该变换器的工作原理进行了详细分析,针对电路存在的功率管换流的关键问题,提出了采用RCD换流电路的解决方案,并对该方案进行了详细分析。通过仿真验证了采用RCD换流电路的AC_Buck变换器的可行性。     

一种新型低功耗采样电阻短路保护电路设计

针对LED驱动电路中采样电阻短路时输出电流持续上升的问题,提出了一种新型的采样电阻短路保护电路。该电路应用于源极驱动模式的LED驱动电路中,在采样电阻短路时能及时关断芯片,有效防止了功率管因电流过大而损坏。与传统采样电阻短路保护电路相比,该新型电路结构简单,并且在提高精度的同时降低了功耗。通过仿真,验证了方案的可行性与优越性。     

基于IR2136与MOSFET的无刷直流电机驱动电路设计

针对传统驱动电路的设计,需要采用相互独立的电源为功率开关管供电,使得硬件结构复杂,可靠性下降,为此,基于功率驱动芯片IR2136与场效应管MOSFET,从信号隔离、三相逆变驱动、过流保护电路等方面,对无刷直流电机驱动电路进行设计。重点阐述了三相逆变驱动电路中的自举电路设计和功率管的驱动保护优化设计。采用TMS570控制板,对该驱动电路进行功能测试,结果表明,设计的驱动电路能够驱动电机平稳运行,且工作稳定可靠。     

BTS660及其在电池智能检测与充电装置中的应用

针对电池智能检测与充放电过程中要进行大电流功率转换的需求,提出了一种利用高精度大电流功率开关来进行电池充放电过程中的大电流功率转换方案。采用Infineon Technologies AG公司生产的BTS660作为大电流功率转换器件,并利用2片BTS660级联来实现充放电过程中的控制,同时重点介绍了其在电池智能检测与充电装置中的应用,并给出了应用电路。结果表明：该方案中的电路工作稳定．并可实现在电压大T70V时的过压保护及短路电流为90A的过流保护,对实现充放电过程中的大电流功率转换起到了良好的转换和保护作用。     

具有短路保护功能的机载功率控制装置设计

介绍了一种具有短路保护功能的功率控制装置,相对于传统的机电接触器,该装置在控制功能上采用场效应管实现,由于无机械触点,在电路通断期间不会频繁切换触点,也不存在机械故障模式,使其具有较高的可靠性和安全性,性能优于传统控制开关,有了短路保护电路,可更好地保护负载和机上电源电路,使得该控制装置更加可靠,实际应用证明该设计具有硬件电路设计简单、实时性好、可靠性强和智能化程度高的优点,符合机载电子设备要求。     

Solid-state circuit breakers and current limiters for medium-voltage systems having distributed power systems

State-of-the-art mechanical circuit breakers in medium-voltage systems allow a safe handling of short-circuits if the short circuit power of the grid is limited. Using delayed turn-off times, the circuit breakers can be coordinated with lower level protection gear. Hence, a high availability of the grid can be guaranteed. However, during a short-circuit a significant voltage sag can be noticed locally in the medium-voltage grid. Sensitive loads such as computers will fail even if the voltage returns within a few seconds. A semiconductor circuit breaker, however, is able to switch fast enough to keep voltage disturbance within acceptable limits. The optimization and selection of power electronic switch topologies is critical. In this paper, different semiconductors are briefly compared considering the requirements of a solid-state switch integrated into a 20-kV medium-voltage grid. Based on these semiconductor characteristics, various switch topologies are developed, which are compared under technical and economical aspects. It is shown that solid-state circuit breakers offer significant advantages when compared to present solutions and can be used in today's medium-voltage power systems.     

基于UCC3800的开关电源的短路保护电路

分析基于UCC3800的开关电源典型电路,指出其短路保护方式在一些场合应用时的缺陷,提出了一种新的短路保护方式,并分析了这种保护方式的工作原理,总结了其在开关电源应用中的优点。     

Integrated overcurrent protection system for class-D audio power amplifiers

A fully integrated overcurrent protection system is presented suitable for application in integrated class-D audio power amplifiers. Accurate overcurrent detection is used based on parallel measurement of the voltage drop across the DMOS power transistors. A logic circuit enables continuous current limiting during overload situations. Actual short circuits can be distinguished from load impedance minima using a simple short-circuit discrimination method.     

High-efficiency dual transistor base drive circuit based on the Cukconverter topology

A dual transistor base drive circuit that unifies all important functions (on-state base current power supply for two power transistors, off-state negative U_be =-5 V base-emitter voltage, overcurrent and short-circuit protection scheme based on saturation voltage, and on- and off-state monitoring circuits) is described. The unit provides two base drive outputs using a single switching converter. It can be used to control two individual power transistors in different inverter configurations, e.g. common emitter or bridge configuration. The concept of a dual transistor base drive circuit using the Cuk switching regulator topology enables the low volume construction of a high-efficiency base drive unit for a high-power transistor inverter bridge leg. The circuit is powered from a common DC rail. The base current waveforms are characterized by steep slopes and an overcurrent peak at turn on     

一种基于数字逻辑控制的低损耗双半桥驱动芯片

设计了一种集成双半桥和四功率开关的驱动芯片。采用双路对称设计,每一路可单独控制使能、自举和驱动。芯片内部采用高精度的基准源以及LDO电路,同时具有欠压死锁、过压保护和过温保护功能。死区控制可避免上下功率管直通大电流,自举设计可使上功率管的开启电压达到5 V,降低了功率管自身的损耗,使功率管输出达到11.90 V。采用TSMC 0.18μm BCD工艺进行流片。测试结果表明,输出的方波信号幅度为11.96 V/11.95 V,死区时间为60 ns/80 ns,静态功耗低至478μA。     

A reverse-voltage protection circuit for MOSFET power switches

When MOSFET is used as a power switch, it is essential to prevent reverse current flow through the parasitic body diodes under reverse voltage condition. A new built-in reverse voltage protection circuit for MOSFETs has been developed. In this design, an area-efficient circuit is used to automatically select the proper well bias voltage to prevent reverse current under the reverse-voltage condition. This built-in reverse protection circuit has been successfully implemented in a high-side power switch application using a 0.6-μm CMOS process. The die area of the protection circuit is only 2.63% of that of a MOSFET. The latch-up immunity is greater than +12 V and -10 V in voltage triggering mode, and greater than ±500 mA in current triggering mode. The protection circuit is not in series with the MOSFET switch, so that the full output swing and high power efficiency are achieved     

一种高速低尖峰电流功率管驱动器电路的设计

利用电荷泵自举原理,提出一种新颖的CMOS驱动电路。该电路在输入信号未进行开关操作时对电容充电,在开关操作发生时,由电荷泵电容和电源一起向负载电容充放电,从而可在不影响充放电时间的前提下降低电源对负载电容的充放电尖峰电流,减小电源噪声。该电路特别适合用来驱动采用高k介质或深槽隔离工艺的功率集成电路,可同时降低上升/下降沿时间和电源尖峰电流,并大幅减小芯片面积。采用中芯国际0.35μm标准CMOS工艺进行流片,测试结果表明,该电路可同时降低负载电容充放电尖峰电流与上升/下降沿时间。     

Automatic Gate Biasing of an SCCMOS Power Switch Achieving Maximum Leakage Reduction and Lowering Leakage Current Variability

Power switch transistors are very effective in cutting the leakage currents of digital circuits in a deep-freeze mode, by de-supplying unused blocks. Among existing power switch transistors, Super Cut-off CMOS (SCCMOS) is the most suited to a low supply voltage environment since it uses a low threshold voltage transistor. This power switch type achieves good leakage reduction results, provided that an optimal voltage is applied on its gate in order to maximize the leakage gain. This optimal voltage value, depending on the operating conditions (process, voltage, temperature), cannot be determined at the design level. A polarization circuit, that automatically finds the optimal bias voltage whatever the environment conditions, was therefore designed and fabricated. This circuit, made in Bulk 65 nm technology, achieves more than two decades leakage current reduction at the power switch level, for a power dissipation overhead of 45 nW at ambient temperature. A very simple scheme is also presented to alleviate the voltage stress applied on the dielectric in case of an ageing of the latter, increasing its time-to-breakdown by several orders of magnitude.