What would happen if someone connected 24V to your12V circuits? If the power and ground lines were inadvertentlyreversed, would the circuits survive? Does yourapplication reside in a harsh environment, where the inputsupply can ring very high or even below ground? Evenif these events are unlikely, it only takes one to destroya circuit board.
上传时间: 2013-10-26
上传用户:jackandlee
A frequent requirement in systems involves drivinganalog signals into non-linear or reactive loads. Cables,transformers, actuators, motors and sample-hold circuitsare examples where the ability to drive diffi cult loads isrequired. Although several power buffer amplifi ers areavailable, none have been optimized for driving diffi cultloads.
上传时间: 2014-12-24
上传用户:1109003457
In a recent discussion with a system designer, the requirementfor his power supply was to regulate 1.5Vand deliver up to 40A of current to a load that consistedof four FPGAs. This is up to 60W of power that must bedelivered in a small area with the lowest height profi lepossible to allow a steady fl ow of air for cooling. Thepower supply had to be surface mountable and operateat high enough effi ciency to minimize heat dissipation.He also demanded the simplest possible solution so histime could be dedicated to the more complex tasks. Asidefrom precise electrical performance, this solution had toremovethe heat generated during DC to DC conversionquickly so that the circuit and the ICs in the vicinity do notoverheat. Such a solution requires an innovative designto meet these criteria:
上传时间: 2013-11-24
上传用户:defghi010
Avalanche photodiodes (APDs) are widely utilized in laserbased fiberoptic systems to convert optical data intoelectrical form. The APD is usually packaged with a signalconditioning amplifier in a small module. An APD receivermodule and attendant circuitry appears in Figure 1. TheAPD module (figure right) contains the APD and a transimpedance(e.g., current-to-voltage) amplifier. An opticalport permits interfacing fiberoptic cable to the APD’sphotosensitive portion. The module’s compact constructionfacilitates a direct, low loss connection between theAPD and the amplifier, necessary because of the extremelyhigh speed data rates involved
上传时间: 2013-10-25
上传用户:brain kung
A recent trend in the design of portable devices has beento use ceramic capacitors to filter DC/DC converter inputs.Ceramic capacitors are often chosen because of theirsmall size, low equivalent series resistance (ESR) and highRMS current capability. Also, recently, designers havebeen looking to ceramic capacitors due to shortages oftantalum capacitors.
上传时间: 2013-11-05
上传用户:comer1123
As logic systems get larger and more complex, theirsupply current requirements continue to rise. Systemsrequiring 100A are fairly common. A high current powersupply to meet such requirements usually requires parallelingseveral power regulators to alleviate the thermalstress on the individual power components. A powersupply designer is left with the choice of how to drive theseparalleled regulators: brute-force single-phase or smartPolyPhaseTM.
上传时间: 2013-10-08
上传用户:zhqzal1014
Photomultipliers (PMT), avalanche photodiodes (APD),ultrasonic transducers, capacitance microphones, radiationdetectors and similar devices require high voltage,low current bias. Additionally, the high voltage must bepristinely free of noise; well under a millivolt is a commonrequirement with a few hundred microvolts sometimesnecessary. Normally, switching regulator confi gurationscannot achieve this performance level without employingspecial techniques. One aid to achieving low noise is thatload currents rarely exceed 5mA. This freedom permitsoutput fi ltering methods that are usually impractical
上传时间: 2013-10-28
上传用户:lhw888
This collection of circuits was worked out between June1991 and July of 1994. Most were designed at customerrequest or are derivatives of such efforts. All representsubstantial effort and, as such, are disseminated here forwider study and (hopefully) use.1 The examples areroughly arranged in categories including power conversion,transducer signal conditioning, amplifiers and signalgenerators. As always, reader comment and questionsconcerning variants of the circuits shown may be addresseddirectly to the author.
上传时间: 2013-11-15
上传用户:凌云御清风
Notebook and palmtop systems need a multiplicity ofregulated voltages developed from a single battery. Smallsize, light weight, and high efficiency are mandatory forcompetitive solutions in this area. Small increases inefficiency extend battery life, making the final productmuch more usable with no increase in weight. Additionally,high efficiency minimizes the heat sinks needed onthe power regulating components, further reducing systemweight and size.
上传时间: 2013-11-11
上传用户:大三三
The LTM4601 DC/DC μModule regulator is a completehigh power density stepdown regulator for up to 12Acontinuous (14A peak) loads. The device is housed ina small 15mm ¥ 15mm ¥ 2.8mm LGA surface mountpackage, thus the large power dissipation is a challengein some applications. This thermal application note willprovide guidelines for using the μModule regulator inambient environments with or without air fl ow. Loadcurrent derating curves are provided for several inputvoltages and output voltages versus ambient temperatureand air fl ow.
上传时间: 2013-10-19
上传用户:bakdesec