The super-junction structure, which has P-type pillar layers as shown left,
realizes high withstand Voltage and ON-resistance lower than the conventional
theoretical limit of silicon.
Applying power to a standard logic chip, SRAM, or EPROM, usually results in output pinstracking the applied Voltage as it rises. Programmable logic attempts to emulate that behavior,but physics forbids perfect emulation, due to the device programmability. It requires care tospecify the pin behavior, because programmable parts encounter unknown variables – yourdesign and your power environment.
Today’s digital systems combine a myriad of chips with different Voltage configurations.Designers must interface 2.5V processors with 3.3V memories—both RAM and ROM—as wellas 5V buses and multiple peripheral chips. Each chip has specific power supply needs. CPLDsare ideal for handling the multi-Voltage interfacing, but do require forethought to ensure correctoperation.
為了提高直接轉矩控制（DTC）系統定子磁鏈估計精度，降低電流、電壓測量的隨機誤差，提出了一種基于擴展卡爾曼濾波（EKF）實現異步電機轉子位置和速度估計的方法。擴展卡爾曼濾波器是建立在基于旋轉坐標系下由定子電流、電壓、轉子轉速和其它電機參量所構成的電機模型上，將定子電流、定子磁鏈、轉速和轉子角位置作為狀態變量，定子電壓為輸入變量，定子電流為輸出變量，通過對磁鏈和轉速的閉環控制提高定子磁鏈的估計精度，實現了異步電機的無速度傳感器直接轉矩控制策略，仿真結果驗證了該方法的可行性,提高了直接轉矩的控制性能。
Abstract:
In order to improve the Direct Torque Control（DTC） system of stator flux estimation accuracy and reduce the current， Voltage measurement of random error， a novel method to estimate the speed and rotor position of asynchronous motor based on extended Kalman filter was introduced. EKF was based on d-p axis motor and other motor parameters （state vector: stator current， stator flux linkage， rotor angular speed and position； input: stator Voltage； output: staror current). EKF was designed for stator flux and rotor speed estimation in close-loop control. It can improve the estimated accuracy of stator flux. It is possible to estimate the speed and rotor position and implement asynchronous motor drives without position and speed sensors. The simulation results show it is efficient and improves the control performance.
Frequently, Voltage reference stability and noise defi nemeasurement limits in instrumentation systems. In particular,reference noise often sets stable resolution limits.Reference Voltages have decreased with the continuingdrop in system power supply Voltages, making referencenoise increasingly important. The compressed signalprocessing range mandates a commensurate reductionin reference noise to maintain resolution. Noise ultimatelytranslates into quantization uncertainty in A to D converters,introducing jitter in applications such as scales, inertialnavigation systems, infrared thermography, DVMs andmedical imaging apparatus. A new low Voltage reference,the LTC6655, has only 0.3ppm (775nV) noise at 2.5VOUT.Figure 1 lists salient specifi cations in tabular form. Accuracyand temperature coeffi cient are characteristic ofhigh grade, low Voltage references. 0.1Hz to 10Hz noise,particularly noteworthy, is unequalled by any low Voltageelectronic reference.
Semiconductor memory, card readers, microprocessors,disc drives, piezoelectric devices and digitally based systemsfurnish transient loads that a Voltage regulator mustservice. Ideally, regulator output is invariant during a loadtransient. In practice, some variation is encountered andbecomes problematic if allowable operating Voltage tolerancesare exceeded. This mandates testing the regulatorand its associated support components to verify desiredperformance under transient loading conditions. Variousmethods are employable to generate transient loads, allowingobservation of regulator response
Automobiles, aircraft, marine vehicles, uninterruptiblepower supplies and telecom hardware represent areasutilizing series connected battery stacks. These stacksof individual cells may contain many units, reaching potentialsof hundreds of volts. In such systems it is oftendesirable to accurately determine each individual cell’sVoltage. Obtaining this information in the presence of thehigh “common mode” Voltage generated by the batterystack is more diffi cult than might be supposed.
