电源芯片-TD6810英文-Datasheet
General Description
The TD6810 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. The device is available in an adjustable version and fixed output voltages of 1.5V and 1.8V.
Supply current during operation is only 20mA and drops to ≤1mA in shutdown. The 2.5V to 5.5V input voltage range makes the TD6810 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems.Automatic Burst Mode operation increases efficiency at light loads, further extending battery life. Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors.The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.6V
feedback reference voltage. The TD6810 is available in a low profile (1mm) TSOT23-5 package.
Features
z High Efficiency: Up to 96%
z High Efficiency at light loads
z Very Low Quiescent Current: Only 20uA During
Operation
z 800mA Output Current
z 2.5V to 5.5V Input Voltage Range z 1.5MHz Constant Frequency Operation z No Schottky Diode Required
z Low Dropout Operation: 100% Duty Cycle z 0.6V Reference Allows Low Output Voltages z Shutdown Mode Draws ≤1uA Supply Current
z Current Mode Operation for Excellent Line and Load
Transient Response z Overtemperature Protected
z Low Profile (1mm) TSOT23-5 Package
Applications
z Cellular Telephones
z Personal Information Appliances z Wireless and DSL Modems z Digital Still Cameras z MP3 Players z Portable Instruments
Package Types
gure 1. Package Types
of TD6810
SOT23-5
Pin Assignments
TSOT23‐5
Pin Name Description
1 RUN
Run Control Input. Forcing this pin above 1.5V enables the part. Forcing this pin below 0.3V shuts down the device. In shutdown, all functions are disabled drawing <1μA supply current. Do not leave RUN floating.
2 GND Ground Pin.
3 SW Switch Node Connection to
Inductor. This pin connects to the drains of the internal main and synchronous power MOSFET switches.
4 VIN Main Supply Pin. Must be closely
decoupled to GND, Pin 2, with a 2.2μF or greater ceramic capacitor.
5 VFB Feedback Pin. Receives the
feedback voltage from an external resistive divider across the output.
5 VOUT
Output Voltage Feedback Pin. An internal resistive divider divides the output voltage down for comparison to the internal reference voltage.
Ordering Information
TD6810 □ □
Circuit Type Output Versions Classifying:
Blank ：Adj 12：1.2V Package 15：1.5V T ：TSOT-23 18：1.8V
Functional Block Diagram
Figure2:Functional Block Diagram of TD6810
Type Application Circuit
Figure 3. Type Application Circuit of TD6810
Absolute Maximum Ratings
Note1: Stresses greater than those listed under Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation
of the device at these or any other conditions above those indicated in the operation is not implied. Exposure to absolute maximum rating conditions for extended
periods may affect reliability.
Parameter Value
Unit Input Supply Voltage -0.3 ~6 V
RUN, VFB Voltages -0.3 ~ VIN V
SW Voltage -0.3V ~(VIN+0.3) V
P-Channel Switch Source Current (DC) 1000 mA
N-Channel Switch Sink Current (DC) 1000 mA
Peak SW Sink and Source Current 1.3 A
Operating Temperature Range -40~+85 oC
Junction Temperature 125 oC
Lead Temperature (Soldering, 10 sec) 300 oC
Storage Temperature Range -65~150 oC
Electrical Characteristics
Unless otherwise specified, VIN= 3.6V TA=25 oC.
Symbol Parameter Conditions Min.
Typ.
Max.
Unit
IVFB Feedback
Current 30
nA
VFB Regulated Feedback
Voltage
TA = 25°C 0.5880 0.6000 0.6120
V
0°C TA ≤ 85°C 0.5865 0.6000 0.6135
–40°C ≤ TA ≤ 85°C 0.5850 0.6000 0.6150
VFB Reference Voltage Line
Regulation
VIN = 2.5V to 5.5V 0.04 0.4 %/ V
VOUT Regulated Output
Voltage
TD6810-1.5, IOUT = 100mA 1.455 1.500 1.545 V
TD6810-1.8, IOUT = 100mA 1.746 1.800 1.854
VOUT Output Voltage Line
Regulation
VIN = 2.5V to 5.5V 0.04 0.4 %/ V
Electrical Characteristics(Cont.)
Unless otherwise specified, VIN= 3.6V TA=25 oC.
Symbol Parameter Conditions Min.
Typ.
Max.
Unit
IPK Peak Inductor Current VIN = 3V, VFB = 0.5V or
VOUT = 90%, Duty Cycle <
35%
1.05 1.10 1.15 A
VLOADREG Output Voltage Load
Regulation
0.5
%
VIN Input Voltage Range 2.5 5.5 V
IS Input DC Bias Current
Active Mode
VFB = 0.5V or VOUT =
90%, ILOAD = 0A
300
400
uA Sleep Mode
VFB = 0.62V or VOUT =
103%, ILOAD = 0A
20
35
uA Shutdown VRUN = 0V, VIN = 4.2V 0.1 1 uA
fOSC
Oscillator Frequency VFB = 0.6V or VOUT =
100%
1 1.5
2 MHz VFB = 0V or VOUT = 0V 400 KHz
RPFET RDS(ON) of P-Channel
FET
ISW = 100mA 0.35 0.45 ?
RNFET RDS(ON) of N-Channel
FET
ISW = -100mA 0.35 0.45 ?
ILSW SW
Leakage VRUN = 0V, VSW = 0V or
5V, VIN = 5V
0.01
1 uA
VRUN RUN
Threshold 0.3
1 1.5
V IRUN RUN Leakage Current 0.01
1 uA
Typical Operating Characteristics
Oscillator Frequency Reference Voltage
Oscillator Frequency vs Supply Voltage
RDS(ON) vs Temperature
Typical Operating Characteristics(Cont.)
Efficiency vs Output Current RDS(ON) vs Input Voltage
Efficiency vs Output Current
Efficiency vs Output Current
Typical Operating Characteristics(Cont.)
Output Voltage vs Output Current Efficiency vs Output Current
Output Voltage vs Output Current Dynamic Supply Current vs Supply Voltage
Typical Operating Characteristics(Cont.)
P-FET Leakage vs Temperature
N-FET Leakage vs Temperature
Efficiency VS Output Current
Function Description
Main Control Loop
The TD6810 uses a constant frequency, current mode step-down architecture. Both the main (P-channel MOSFET) and synchronous (N-channel MOSFET) switches are internal. During normal operation, the internal top power MOSFET is turned on each cycle when the oscillator sets the RS latch, and turned off when the current comparator, ICOMP, resets the RS latch. The peak inductor current at which ICOMP resets the RS latch, is controlled by
the output of error amplifier EA. When the load current increases, it causes a slight decrease in the feedback voltage, FB, relative to the 0.6V reference, which in turn, causes the EA amplifier’s output voltage to increase until the average inductor current matches the new load current. While the top MOSFET is off, the bottom MOSFET is turned on until either the inductor current starts to reverse, as indicated by the current reversal comparator IRCMP, or the beginning of the next clock cycle.
Burst Mode Operation
The TD6810 is capable of Burst Mode operation in which the internal power MOSFETs operate intermittently based on load demand.
In Burst Mode operation, the peak current of the inductor is set to approximately 200mA regardless of the output load. Each burst event can last from a few cycles at light loads to almost continuously cycling with short sleep intervals at moderate loads. In between these burst events, the power MOSFETs and any unneeded circuitry are turned off, reducing the quiescent current to 20mA. In this sleep state, the load current is being supplied solely from the output capacitor. As the output voltage droops, the EA amplifier’s output rises above the sleep threshold signaling the BURST comparator to trip and turn the top MOSFET on. This process repeats at a rate that is dependent on the load demand.
Short-Circuit Protection
When the output is shorted to ground, the frequency of the oscillator is reduced to about 400kHz, 1/4 the nominal frequency. This frequency foldback ensures that the inductor current has more time to decay, thereby preventing runaway. The oscillator’s frequency will progressively increase to 1.5MHz when VFB or VOUT rises above 0V.
Dropout Operation
As the input supply voltage decreases to a value approaching the output voltage, the duty cycle increases toward the maximum on-time. Further reduction of the supply voltage forces the main switch to remain on for more than one cycle until it reaches 100% duty cycle. The output voltage will then be determined by the input voltage minus the voltage drop across the P-channel MOSFET and the inductor.
An important detail to remember is that at low input supply voltages, the RDS(ON) of the P-channel switch increases (see Typical Performance Characteristics). Therefore, the user should calculate the power dissipation when the TD6810 is used at 100% duty cycle with low input voltage (See Thermal Considerations in the Applications Information
section).
Function Description(Cont.)
Low Supply Operation
The TD6810 will operate with input supply voltages as
low as 2.5V, but the maximum allowable output current is
reduced at this low voltage. Figure 2 shows the reduction
in the maximum output current as a function of input
voltage for various output voltages.
Slope Compensation and Inductor Peak
Current
Slope compensation provides stability in constant
frequency architectures by preventing subharmonic
oscillations at high duty cycles. It is accomplished
internally by adding a compensating ramp to the inductor
current signal at duty cycles in excess of 40%. Normally,
this results in a reduction of maximum inductor peak
current for duty cycles >40%. However, the TD6810 uses
a patent-pending scheme that counteracts this
compensating ramp, which allows the maximum inductor
peak current to remain unaffected throughout all duty
cycles.
Maximum Output Current vs Input Voltag
The basic TD6810 application circuit is shown in Figure
3. External component selection is driven by the load
requirement and begins with the selection of L followed
by CIN and COUT.
Inductor Selection
For most applications, the value of the inductor will fall in
the range of 1uH to 4.7uH. Its value is chosen based on
the desired ripple current. Large value inductors lower
ripple current and small value inductors result in higher
ripple currents. Higher VIN or VOUT also increases the
ripple current as shown in equation 1. A reasonable
starting point for setting ripple current is DIL = 320mA
(40% of 800mA).
The DC current rating of the inductor should be at least
equal to the maximum load current plus half the ripple
current to prevent core saturation. Thus, a 920mA rated
inductor should be enough for most applications (800mA
+ 120mA). For better efficiency, choose a low
DC-resistance
inductor.
The inductor value also has an effect on Burst Mode
operation. The transition to low current operation begins
when the inductor current peaks fall to approximately
200mA. Lower inductor values (higher DIL) will cause
this to occur at lower load currents, which can cause a
dip in efficiency in the upper range of low current
operation. In Burst Mode operation, lower inductance
values will cause the burst frequency to increase.
Function Description(Cont.)
Inductor Core Selection
Different core materials and shapes will change the
size/current and price/current relationship of an inductor.
Toroid or shielded pot cores in ferrite or permalloy
materials are small and don’t radiate much energy, but
generally cost more than powdered iron core inductors
with similar electrical characteristics. The choice of which
style inductor to use often depends more on the price vs
size requirements and any radiated field/EMI
requirements than on what the TD6810 requires to
operate. Table 1 shows some typical surface mount
inductors that work well in TD6810 applications.
Table 1. Representative Surface Mount Inductors
CIN and COUT Selection
In continuous mode, the source current of the top
MOSFET is a square wave of duty cycle VOUT/VIN. To
prevent large voltage transients, a low ESR input
capacitor sized for the maximum RMS current must be
used. The maximum RMS capacitor current is given by:
This formula has a maximum at VIN = 2VOUT, where
IRMS = IOUT/2. This simple worst-case condition is
commonly used for design because even significant
deviations do not offer much relief. Note that the
capacitor manufacturer’s ripple current ratings are often
based on 2000 hours of life. This makes it advisable to
further derate the capacitor, or choose a capacitor rated
at a higher temperature than required. Always consult
the manufacturer if there is any question.
The selection of COUT is driven by the required effective
series resistance (ESR). Typically, once the ESR
requirement for COUT has been met, the RMS current
rating generally far exceeds the IRIPPLE(P-P)
requirement. The output ripple DVOUT is determined by:
where f = operating frequency, COUT = output
capacitanceand DIL = ripple current in the inductor. For a
fixed output voltage, the output ripple is highest at
maximum input voltage since DIL increases with input
voltage.
Aluminum electrolytic and dry tantalum capacitors are
both available in surface mount configurations. In the
case of tantalum, it is critical that the capacitors are
surge tested for use in switching power supplies. An
excellent choice is the AVX TPS series of surface mount
tantalum. These are specially constructed and tested for
low ESR so they give the lowest ESR for a given volume.
Other capacitor types include Sanyo POSCAP, Kemet
T510 and T495 series, and Sprague 593D and 595D
series. Consult the manufacturer for other specific
recommendations.
Function Description(Cont.)
Using Ceramic Input and Output Capacitors
Higher values, lower cost ceramic capacitors are now becoming available in smaller case sizes. Their high ripple current, high voltage rating and low ESR make them ideal for switching regulator applications. Because the TD6810’s control loop does not depend on the output capacitor’s ESR for stable operation, ceramic capacitors can be used freely to achieve very low output ripple and small circuit size.
However, care must be taken when ceramic capacitors are used at the input and the output. When a ceramic capacitor is used at the input and the power is supplied by a wall adapter through long wires, a load step at the output can induce ringing at the input, VIN. At best, this ringing can couple to the output and be mistaken as loop instability. At worst, a sudden inrush of current through the long wires can potentially cause a voltage spike at VIN, large enough to damage the part.
When choosing the input and output ceramic capacitors, choose the X5R or X7R dielectric formulations. These dielectrics have the best temperature and voltage characteristics of all the ceramics for a given value and size.
Output Voltage Programming
In the adjustable version, the output voltage is set by a resistive divider according to the following formula:
The external resistive divider is connected to the output, allowing remote voltage sensing as shown in Figure4.
Figure 4:Setting the output Voltage
Vout R1 R2
1.2V 150K 150K
1.5V
160K 240K
1.8V 150K 300K
2.5V 150K 470K
3.3V 150K 680K
Table 2. Vout VS. R1, R2, Cf Select Table Efficiency Considerations
The efficiency of a switching regulator is equal to the output power divided by the input power times 100%. It is often useful to analyze individual losses to determine what is limiting the efficiency and which change would produce the most improvement. Efficiency can be expressed as:
Efficiency = 100% – (L1 + L2 + L3 + ...)
where L1, L2, etc. are the individual losses as a percentage of input power.
Although all dissipative elements in the circuit produce losses, two main sources usually account for most of the losses in TD6810 circuits: VIN quiescent current and I2R losses. The VIN quiescent current loss dominates the efficiency loss at very low load currents whereas the I2R loss dominates the efficiency loss at medium to high load currents. In a typical efficiency plot, the efficiency curve at very low load currents can be misleading since the actual power lost is of no consequence as illustrated in Figure 5.
Function Description(Cont.)
Figure 4:Power Lost VS Load Current
1. The VIN quiescent current is due to two components: the DC bias current as given in the electrical characteristics and the internal main switch and synchronous switch gate charge currents. The gate charge current results from switching the gate capacitance of the internal power MOSFET switches. Each time the gate is switched from high to low to high again, a packet of charge, dQ, moves from VIN to ground. The resulting dQ/dt is the current out of VIN that is typically larger than
the DC bias current. In continuous mode, IGATECHG
=f(QT + QB) where QT and QB are the gate charges of the internal top and bottom switches. Both the DC bias and gate charge losses are proportional to VIN and thustheir effects will be more pronounced at higher supply voltages.
2. I2R losses are calculated from the resistances of the internal switches, RSW, and external inductor RL. In continuous mode, the average output current flowing through inductor L is “chopped” between the main switch and the synchronous switch. Thus, the series resistance looking into the SW pin is a function of both top and bottom MOSFET RDS(ON) and the duty cycle (DC) as follows: RSW = (RDS(ON)TOP)(DC) + (RDS(ON)BOT)(1 – DC) The RDS(ON) for both the top and bottom MOSFETs can be obtained from the Typical Performance Charateristics curves. Thus, to obtain I2R losses, simply add RSW to RL and multiply the result by the square of the average output current. Other losses including CIN and COUT ESR dissipative losses and inductor core losses generally account for less than 2% total additional loss.
Thermal Considerations
In most applications the TD6810 does not dissipate much heat due to its high efficiency. But, in applications where the TD6810 is running at high ambient temperature with low supply voltage and high duty cycles, such as in dropout, the heat dissipated may exceed the maximum junction temperature of the part. If the junction temperature reaches approximately 150°C, both power switches will be turned off and the SW node will become high impedance.
To avoid the TD6810 from exceeding the maximum junction temperature, the user will need to do some thermal analysis. The goal of the thermal analysis is to determine whether the power dissipated exceeds the maximum junction temperature of the part. The temperature rise is given by:
TR = (PD)(qJA)
where PD is the power dissipated by the regulator and qJA is the thermal resistance from the junction of the die to the ambient temperature.
The junction temperature, TJ, is given by:
TJ = TA + TR
where TA is the ambient temperature.
As an example, consider the TD6810 in dropout at an input voltage of 2.7V, a load current of 800mA and an ambient temperature of 70°C. From the typical performance graph of switch resistance, the RDS(ON) of the P-channel switch at 70°C is approximately 0.52W.
Function Description(Cont.)
Therefore,
power dissipated by the part is:
PD = ILOAD 2 ? RDS(ON) = 187.2mW
For the SOT-23 package, the qJA is 250°C/ W. Thus, the
junction temperature of the regulator is:
TJ = 70°C + (0.1872)(250) = 116.8°C
which is below the maximum junction temperature of
125°C.
Note that at higher supply voltages, the junction
temperature is lower due to reduced switch resistance
(RDS(ON)).
Checking Transient Response
The regulator loop response can be checked by looking
at the load transient response. Switching regulators take
several cycles to respond to a step in load current. When
a load step occurs, VOUT immediately shifts by an
amount equal to (ΔILOAD ? ESR), where ESR is the
effective series resistance of COUT. ΔILOAD also begins
to charge or discharge COUT, which generates a
feedback error signal. The regulator loop then acts to
return VOUT to its steadystate value. During this
recovery time VOUT can be monitored for overshoot or
ringing that would indicate a stability problem.
A second, more severe transient is caused by switching
in loads with large (>1μF) supply bypass capacitors. The
discharged bypass capacitors are effectively put in
parallel with COUT, causing a rapid drop in VOUT. No
regulator can deliver enough current to prevent this
problem if the load switch resistance is low and it is
driven quickly. The only solution is to limit the rise time of
the switch drive so that the load rise time is limited to
approximately (25 ? CLOAD).Thus, a 10μF capacitor
charging to 3.3V would require a 250μs rise time, limiting
the charging current to about 130mA.
Package Information
TSOT23-5 Package Outline Dimensions
Design Notes
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英文论文及中文翻译
International Journal of Minerals, Metallurgy and Materials Volume 17, Number 4, August 2010, Page 500 DOI: 10.1007/s12613-010-0348-y Corresponding author: Zhuan Li E-mail: li_zhuan@https://www.sodocs.net/doc/1119231141.html, ? University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg 2010 Preparation and properties of C/C-SiC brake composites fabricated by warm compacted-in situ reaction Zhuan Li, Peng Xiao, and Xiang Xiong State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China (Received: 12 August 2009; revised: 28 August 2009; accepted: 2 September 2009) Abstract: Carbon fibre reinforced carbon and silicon carbide dual matrix composites (C/C-SiC) were fabricated by the warm compacted-in situ reaction. The microstructure, mechanical properties, tribological properties, and wear mechanism of C/C-SiC composites at different brake speeds were investigated. The results indicate that the composites are composed of 58wt% C, 37wt% SiC, and 5wt% Si. The density and open porosity are 2.0 g·cm–3 and 10%, respectively. The C/C-SiC brake composites exhibit good mechanical properties. The flexural strength can reach up to 160 MPa, and the impact strength can reach 2.5 kJ·m–2. The C/C-SiC brake composites show excellent tribological performances. The friction coefficient is between 0.57 and 0.67 at the brake speeds from 8 to 24 m·s?1. The brake is stable, and the wear rate is less than 2.02×10?6 cm3·J?1. These results show that the C/C-SiC brake composites are the promising candidates for advanced brake and clutch systems. Keywords: C/C-SiC; ceramic matrix composites; tribological properties; microstructure [This work was financially supported by the National High-Tech Research and Development Program of China (No.2006AA03Z560) and the Graduate Degree Thesis Innovation Foundation of Central South University (No.2008yb019).] 温压-原位反应法制备C / C-SiC刹车复合材料的工艺和性能 李专，肖鹏，熊翔 粉末冶金国家重点实验室，中南大学，湖南长沙410083，中国（收稿日期：2009年8月12日修订：2009年8月28日;接受日期：2009年9月2日） 摘要：采用温压?原位反应法制备炭纤维增强炭和碳化硅双基体(C/C-SiC)复合材
C语言中英文翻译资料
一．C语言关键字对照 关键字，又称保留字，是C语言中已预先定义、具有特定含义的标识符。 注：C语言中共有32个关键字，所有关键字都用小写字母表示，且这些关键字不能用作用户标识符。即关键字由系统定义，具有特定的含义，不能重作其它定义。 32个关键字如下： 1．数据定义 C语言中所有的变量都具有某种类型，其定义的基本格式是：类型变量名； int：整型 short：短整型 long：长整型 signed：有符号型 unsigned：无符号型 char：字符型 float：单精度型 double：双精度型 const：定义常量 typedef：类型定义 2．存储类别 一般在变量的定义前面，用于指定变量的存储类别，如果缺省的话，则默认是auto。 auto：自动变量 static：静态变量 register：寄存器变量 extern：外部变量 3．结构 C语言中除了提供一些基本数据类型外，还提供了结构体，共有体以及枚举，用来实现多个变量的集合表示。 struct：结构体 union：共用体 enum：枚举类型 4．语句 C语言中提供了一些语句来实现程序的基本结构。 if：条件判断（假如） else：不满足条件（否则） for：循环 do：与while一起使用，直到型循环 while：当型循环 goto：无条件跳转语句 switch：多分支选择语句 case：分支，在switch语句块中表示不同的分支
default：缺省，一般在switch语句中使用 continue：继续（结束本次循环） break：中断（跳出整个循环） return：返回 void：空类型（用于函数没有返回值时） 5．预处理 ＃define：定义一个宏名来代替一个字符串 ＃include：引入程序所需要的头文件 ＃undef：条件编译 ＃ifdef：假如定义 ＃ifndef：假如没有定义 6．其他 sizeof：用于计算所占内存空间的大小 volatile： C语言关键字volatile（注意它是用来修饰变量而不是上面介绍的__volatile__）表明某个变量的值可能在外部被改变，因此对这些变量的存取不能缓存到寄存器，每次使用时需要重新存取 二．Turboc2.0 环境中常用的关键词 File(文件) Load（加载） New（新建） Save（保存） Write to（另存为） Directory（目录） Change dir（改变目录） Quit（结束） Run（运行） Program reset（程序重置） Goto cursor（运行到光标处） Trace into（跟踪） Step over（单部执行） Compile（编译） Compile to obj（编译成目标文件） Make EXE file（制作可执行文件） Link EXE file（链接可执行文件） Build all（创建全部） Options（选项）
现代电源技术发展历程概述[精编版]
现代电源技术发展历程概述[精编版] 现代电源技术发展历程 2007-08-23 现代电源技术是应用电力电子半导体器件，综合自动控制、计算机(微处理器)技术和电磁技术的多学科边缘交又技术。在各种高质量、高效、高可靠
性的电源中起关键作用，是现代电力电子技术的具体应用。
当前，电力电子作为节能、节才、自动化、智能化、机电一体化的基础，正朝着应用技术高频化、硬件结构模块化、产品性能绿色化的方向发展。在不远的将来，电力电子技术将使电源技术更加成熟、经济、实用，实现高效率和高品质用电相结合。 1. 电力电子技术的发展 现代电力电子技术的发展方向，是从以低频技术处理问题为主的传统电力电子学，向以高频技术处理问题为主的现代电力电子学方向转变。电力电子技术起始于五十年代末六十年代初的硅整流器件，其发展先后经历了整流器时代、逆变器时代和变频器时代，并促进了电力电子技术在许多新领域的应用。八十年代末期和九十年代初期发展起来的、以功率MOSFET和IGBT为代表的、集高频、高压和大电流于一身的功率半导体复合器件，表明传统电力电子技术已经进入现代电力电子时代。 1.1 整流器时代
大功率的工业用电由工频(50Hz)交流发电机提供，但是大约20%的电能 是以直流形式消费的，其中最典型的是电解(有色金属和化工原料需要直流电解)、牵引(电气机车、电传动的内燃机车、地铁机车、城市无轨电车等)和直流传动(轧钢、造纸等)三大领域。大功率硅整流器能够高效率地把工频交流电转变为直流电，因此在六十年代和七十年代，大功率硅整流管和晶闸管的开发与应用得以很大发展。当时国内曾经掀起了-股各地大办硅整流器厂的热潮，目前全国大大小小的制造硅整流器的半导体厂家就是那时的产物。 1.2 逆变器时代 七十年代出现了世界范围的能源危机，交流电机变频惆速因节能效果显著而迅速发展。变频调速的关键技术是将直流电逆变为0~100Hz的交流电。在七十年代到八十年代，随着变频调速装置的普及，大功率逆变用的晶闸管、巨型功率晶体管(GTR)和门极可关断晶闸管(GT0)成为当时电力电子器件的主角。类似的应用还包括高压直流输出，静止式无功功率动态补偿等。这时的电力电子技术已经能够实现整流和逆变，但工作频率较低，仅局限在中低频范围内。
半导体芯片行业全梳理(附股)
半导体芯片行业全梳理（附股） 去年开始，半导体芯片行业得到了资金的认可，直到现 在，仍有很多上市公司被持续爆炒。在信息技术高速发展的今天，大数据是资源，堪比新经济的石油；5G 是道路，决定信息的传输速度；芯片是核心，是数据分析的大脑。不管 是工业互联网、人工智能、虚拟现实、影音娱乐、汽车数码， 新产业的发展都要围绕这三个行业进行，所以大数据、5G 和半导体芯片是工业4.0 的根基，是所有新兴行业的根本。 今天聊半导体！长期以来，我国集成电路产业都是逆差，严重依赖国外进口，每年进口芯片超2000 亿美元。2014 年9 月，千亿规模的国家集成电路产业基金（以下简称“大基金”） 成立，扮演着产业扶持与财务投资的双重角色。目前大基金已成为11 家A 股上市公司的股东，而且大基金还将参与多家公司的增发而获得股权。大基金代表国家集成电路产业的发展方向，其投资的上市公司值得投资者关注，下面梳理 大基金持股A 股公司情况。国科微：持股15.79% ，二股东；三安光电、兆易创新、通富微电、北斗星通：持股超10% ；长电科技：9.54% 晶方科技：9.32% 北方华创：7.5% 长川科技：7.5%纳斯达：4.29% 同时，大基金将参与长电科技、通 富微电、万盛股份、景嘉微、雅克科技、耐威科技的增发， 增发完成后，大基金持股情况如下：长电科技：19% 通富微
电：15.7% 万盛股份：7.41%雅克科技：5.73%此外大基金 还投资了华天科技的子公司，入股士兰微生产线，与巨化股关注，但半导体到底是怎样的一个行业，我们简单梳理一下。 份合作发展电子化学材料。大基金加持的A 股公司可以重点 半导体分为四类产品，分别是集成电路、光电子器件、分立器件和传感器。其中规模最大的是集成电路，市场规模达到 2,753 亿美元，占半导体市场的81% ，所以有时大家会把半导体行业跟集成电路混为一谈。从半导体产业链上下游来看：半导体产业链上中下游全梳理：上游：IC设计、半导体材料、半导体设备一、IC 设计重点关注：兆易创新：国内存储器及 MCU 芯片产业的龙头企业，主营业务存储芯片是国家战略支持的IC 细分方向。大基金战略入股，公司将成为国家存储器战略落地的产业平台之一。韦尔股份：模拟芯片龙头。 公司是国内鲜有的同时具备强大半导体设计和IC 分销实力的公司，业务模式独特。公司主营业务为半导体分立器件、电源管理IC 等半导体这些产品广泛应用于移动通信、车载电子、安防、网络通信、家用电器等领域。国科微：公司是国家高新技术企业和经工业和信息化部认定的集成电路设计企业，长期致力于大规模集成电路的设计、研发及销售。 在广播电视芯片市场，公司长期保持直播卫星市场的龙头地位，占有绝对的市场份额。弘信电子：高速成长的国内柔性印制电路板 （FPC ）龙头。公司当前主营FPC 研发、设计、
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毕业设计说明书 英文文献及中文翻译 学院：专 2011年6月 电子与计算机科学技术软件工程
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有关交通灯中英文翻译资料
当今时代是一个自动化时代，交通灯控制等很多行业的设备都与计算机密切相关。因此，一个好的交通灯控制系统，将给道路拥挤、违章控制等方面给予技术革新。随着大规模集成电路及计算机技术的迅速发展，以及人工智能在控制技术方面的广泛运用，智能设备有了很大的发展，是现代科技发展的主流方向。本文介绍了一个智能交通灯系统的设计。该智能交通灯控制系统可以实现的功能有：对某市区的四个主要交通路口进行监控；各路口有固定的工作周期，并且在道路拥挤时中控中心能改变其周期；对路口违章的机动车能够即时拍照，并提取车牌号。在世界范围内，一个以微电子技术，计算机和通信技术为先导的，以信息技术和信息产业为中心的信息革命方兴未艾。而计算机技术怎样与实际应用更有效的结合并有效的发挥其作用是科学界最热门的话题，也是当今计算机应用中空前活跃的领域。本文主要从单片机的应用上来实现十字路口交通灯智能化的管理，用以控制过往车辆的正常运作。 The times is a automation times nowadays , traffic light waits for much the industry
equipment to go hand in hand with the computer under the control of. Therefore, a good traffic light controls system , will give road aspect such as being crowded , controlling against rules to give a technical improvement. With the fact that the large-scale integrated circuit and the computer art promptness develop, as well as artificial intelligence broad in the field of control technique applies, intelligence equipment has had very big development , the main current being that modern science and technology develops direction. The main body of a book is designed having introduced a intelligence traffic light systematically. The function being intelligence traffic light navar's turn to be able to come true has: The crossing carries out supervisory control on four main traffic of some downtown area; Every crossing has the fixed duty period , charges centre for being able to change it's period and in depending on a road when being crowded; The motor vehicle breaking rules and regulations to the crossing is able to take a photo immediately , abstracts and the vehicle shop sign. Within world range, one uses the microelectronics technology , the computer and the technology communicating by letter are a guide's , centering on IT and IT industry information revolution is in the ascendant. But, how, computer art applies more effective union and there is an effect's brought it's effect into play with reality is the most popular topic of conversation of scientific community , is also that computer applications is hit by the unparalleled active field nowadays. The main body of a book is applied up mainly from slicing machine's only realizing intellectualized administration of crossroads traffic light , use opera tion in controlling the vehicular traffic regularity.
现代电力电子电源技术发展
现代电力电子及电源技术的发展 现代电源技术是应用电力电子半导体器件,综合自动控制、计算机(微处理器)技术和电磁技术的多学科边缘交又技术。在各种高质量、高效、高可靠性的电源中起关键作用,是现代电力电子技术的具体应用。 当前,电力电子作为节能、节才、自动化、智能化、机电一体化的基础,正朝着应用技术高频化、硬件结构模块化、产品性能绿色化的方向发展。在不远的将来,电力电子技术将使电源技术更加成熟、经济、实用,实现高效率和高品质用电相结合。 1. 电力电子技术的发展 现代电力电子技术的发展方向,是从以低频技术处理问题为主的传统电力电子学,向以高频技术处理问题为主的现代电力电子学方向转变。电力电子技术起始于五十年代末六十年代初的硅整流器件,其发展先后经历了整流器时代、逆变器时代和变频器时代,并促进了电力电子技术在许多新领域的应用。八十年代末期和九十年代初期发展起来的、以功率MOSFET和IGBT 为代表的、集高频、高压和大电流于一身的功率半导体复合器件,表明传统电力电子技术已经进入现代电力电子时代。 1.1 整流器时代 大功率的工业用电由工频(50Hz)交流发电机提供,但是大约20%的电能是以直流形式消费的,其中最典型的是电解(有色金属和化工原料需要直流电解)、牵引(电气机车、电传动的燃机车、地铁机车、城市无轨电车等)和直流传动(轧钢、造纸等)三大领域。大功率硅整流器能够高效率地把工频交流电转变为直流电,因此在六十年代和七十年代,大功率硅整流管和晶闸管的开发与应用得以很大发展。当时国曾经掀起了-股各地大办硅整流器厂的热潮,目前全国大大小小的制造硅整流器的半导体厂家就是那时的产物。
精益生产英文资料介绍
精益生产英文资料介绍 1,General questions about lean operations 1.1,What is lean? Lean operations involve the elimination of waste, whether it be time, materials, efficiency or processes. It also means figuratively tightening the belt in pursuit of increased productivity gains that will increase a company’s ability to compete more successfully. 1.2,Why lean? Increased global competition will likely force all but the strong to the sidelines. Belt tightening and a lean mindset will enable the game to continue as companies steady themselves for the challenges and opportunities that await them. The truly lean company of today will be a survivor in the global battle for customers and bottom line profits. The need for lean is obvious and the potential rewards are dazzling. There will be those who will probably resist the necessary changes. Training will start you on the road to overcoming this resistance and ultimately achieving a successful transition. 1.3,Who participates in lean Operations? Eventually, everyone in the company is a participant in the quest for a lean organization. 1.4,Is lean applicable only to manufacturing? The concept includes many non-manufacturing areas such as purchasing, clerical, office and technical. Also, these areas often contribute in making lean achievements in manufacturing more successful. 1.5,What organizations can benefit from lean projects? Every organization offers goods or services. This includes such diverse sectors as merchandising, hospitals, banking, insurance, public utilities, government, military, prisons, churches, schools and, of course, manufacturing. 1.6,Can lean activities be started in more than one division at a time? Yes, it can be done, but starting in one division is preferable. The experience
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半导体工业的发展概况(上) 1 半导体硅工业的发展 随着社会的发展，直到20世纪时，世人才发现硅具有半导体的性质。这些性质包括其电阻率随着温度的增加而递减、光电效应、热电效应、磁电效应、霍尔效应及其与金属接触的整流效应等。 继硅晶体管发明之后，虽然可利用乔赫拉斯基法来制备硅单晶体，但是由于直拉(CZ)法生长的硅单晶，因由于使用的石英坩埚会受到硅熔体的侵蚀而增加氧的沾污。为了获得高纯度的硅单晶体，1956年HenryTheurer发明了区熔法(FZ)[6]。区熔法因没有使用石英坩埚容器，故不存在氧污染的问题。之后，在1958年由于DashFI发明了一种五位错单晶生长法，才使得生长优质大直径硅单晶技术得到了不断发展。1958年，Kilby(基尔比)在美国德州仪器公司发明了集成电路[8]，奠定了信息时代到来的基础。第一代IC(集成电路)问世后，半导体工业迅速得到了发展，晶片上的电子元器件的密度和复杂性，也就从小规模集成电路(SSI)向中规模集成电路(MSB、大规模集成电路(LSB、超大规模集成电路(VLSI)、甚大规模集成电路(ULSI)不断地发展。集成电路的应用范围相当广泛，按不同的用途集成电路的分类见图1所示”。
以硅材料为主的半导体专用材料已是电子信息产业最重要的基础、功能材料，在国民经济和军事工业中占有很重要的地位。全世界的半导体器件中有95％以上是用硅材料制成，其中85％的集成电路也是由硅材料制成。 2 国外半导体工业发展动态 随着IC工艺、技术的不断发展，硅单晶的直径尺寸越做越大，40多年来，小于中200mm的硅单晶片已经进入商业生产应用的水平，中300mm 的硅单晶抛光片也已在特征尺寸线宽小于0．13μm的IC器件工艺中得到了广泛应用，并已进入了研制、生产的阶段，中400mm的硅单晶也进入了开发、研究的阶段。纳米电子技术必将成为今后研究和发展的方向。 2．1 硅集成电路发展现状 制备集成电路用的硅单晶直径研制发展历史见表1所示。
中文和英文简历和专业英语材料翻译
韶关学院 期末考核报告 科目：专业英语 学生姓名： 学号： 同组人： 院系： 专业班级： 考核时间：2012年10月9日—2012年11月1 日评阅教师： 评分：
第1章英文阅读材料翻译 (1) 第2章中文摘要翻译英文 (3) 第3章中文简历和英文简历 (4) 第4章课程学习体会和建议 (6) 参考文献 (7)
第1章英文阅读材料翻译 Mechanization and Automation Processes of mechanization have been developing and becoming more complex ever since the beginning of the Industrial Revolution at the end of the 18th century. The current developments of automatic processes are, however, different from the old ones. The “automation” of the 20th century is distinct from the mechanization of the 18th and 19th centuries inasmuch as mechanization was applied to individual operations, wherea s “automation” is concerned with the operation and control of a complete producing unit. And in many, though not all, instances the element of control is so great that whereas mechanization displaces muscle, “automation”displaces brain as well. The distinction between the mechanization of the past and what is happening now is, however, not a sharp one. At one extreme we have the electronic computer with its quite remarkable capacity for discrimination and control, while at the other end of the scale are “ transfer machines” , as they are now called, which may be as simple as a conveyor belt to another. An automatic mechanism is one which has a capacity for self-regulation; that is, it can regulate or control the system or process without the need for constant human attention or adjustment. Now people often talk about “feedback” as begin an essential factor of the new industrial techniques, upon which is base an automatic self-regulating system and by virtue of which any deviation in the system from desired condition can be detected, measured, reported and corrected. when “feedback” is applied to the process by which a large digital computer runs at the immense speed through a long series of sums, constantly rejecting the answers until it finds one to fit a complex set of facts which have been put to it, it is perhaps different in degree from what we have previously been accustomed to machines. But “feedback”, as such, is a familiar mechanical conception. The old-fashioned steam engine was fitted with a centrifugal governor, two balls on levers spinning round and round an upright shaft. If the steam pressure rose and the engine started to go too fast, the increased speed of the spinning governor caused it to rise up the vertical rod and shut down a valve. This cut off some of the steam and thus the engine brought itself back to its proper speed. The mechanization, which was introduced with the Industrial Revolution, because it was limited to individual processes, required the employment of human labor to control each machine as well as to load and unload materials and transfer them from one place to another. Only in a few instances were processes automatically linked together and was production organized as a continuous flow. In general, however, although modern industry has been highly mechanized ever since the 1920s, the mechanized parts have not as a rule been linked together. Electric-light bulbs, bottles and the components of innumerable mass-produced
机械专业外文翻译(中英文翻译)
外文翻译 英文原文 Belt Conveying Systems Development of driving system Among the methods of material conveying employed，belt conveyors play a very important part in the reliable carrying of material over long distances at competitive cost．Conveyor systems have become larger and more complex and drive systems have also been going through a process of evolution and will continue to do so．Nowadays，bigger belts require more power and have brought the need for larger individual drives as well as multiple drives such as 3 drives of 750 kW for one belt(this is the case for the conveyor drives in Chengzhuang Mine)．The ability to control drive acceleration torque is critical to belt conveyors’performance．An efficient drive system should be able to provide smooth，soft starts while maintaining belt tensions within the specified safe limits．For load sharing on multiple drives．torque and speed control are also important considerations in the drive system’s design. Due to the advances in conveyor drive control technology，at present many more reliable．Cost-effective and performance-driven conveyor drive systems covering a wide range of power are available for customers’ choices[1]. 1 Analysis on conveyor drive technologies 1．1 Direct drives Full-voltage starters．With a full-voltage starter design，the conveyor head shaft is direct-coupled to the motor through the gear drive．Direct full-voltage starters are adequate for relatively low-power, simple-profile conveyors．With direct fu11-voltage starters．no control is provided for various conveyor loads and．depending on the ratio between fu11-and no-1oad power requirements，empty starting times can be three or four times faster than full load．The maintenance-free starting system is simple，low-cost and very reliable．However, they cannot control starting torque and maximum stall torque；therefore．they are