Linear Technology’s DC/DC step-down μModule®regulators are complete switchmode power supplies in asurface-mount package. They include the DC/DC controller,inductor, power switches and supporting circuitry.These highly integrated regulators also provide an easysolution for applications that require negative outputvoltages. In other words, these products can operate asinverting buck-boost regulators. As a result, the lowestpotential in the circuit is not the standard 0V, but –VOUT,which must be tied to the μModule regulator’s GND. Allsignals are now referred to –VOUT.
上傳時間: 2013-10-22
上傳用戶:ztj182002
Abstract: This article discusses future trends in the design of smartphones and other consumer products. The discussion focuses onthe importance of integration, which saves valuable PCB space and drives down costs.
上傳時間: 2014-01-13
上傳用戶:lhw888
Telecommunication, satellite links and set-top boxes allrequire tuning a high frequency oscillator. The actualtuning element is a varactor diode, a 2-terminal device thatchanges capacitance as a function of reverse bias voltage.1 The oscillator is part of a frequency synthesizingloop, as detailed in Figure 1. A phase locked loop (PLL)compares a divided down representation of the oscillatorwith a frequency reference. The PLL’s output is levelshifted to provide the high voltage necessary to bias thevaractor, which closes a feedback loop by voltage tuningthe oscillator. This loop forces the voltage controlledoscillator (VCO) to operate at a frequency determined bythe frequency reference and the divider’s division ratio.
上傳時間: 2013-12-20
上傳用戶:ABCDE
Switching regulators are of universal interest. LinearTechnology has made a major effort to address this topic.A catalog of circuits has been compiled so that a designengineer can swiftly determine which converter type isbest. This catalog serves as a visual index to be browsedthrough for a specific or general interest.
標簽: Collection Switching Regulator Circuit
上傳時間: 2013-11-09
上傳用戶:mh_zhaohy
Linear Technology has a sabbatical program. Every fiveyears employees are granted sabbatical leave, which maylast up to six weeks. You have 18 months from each fiveyear employment anniversary to take the leave. Sabbaticalis fully company paid and has no restrictions. The time isyours to do with as you please.
上傳時間: 2013-10-19
上傳用戶:851197153
For a variety of reasons, it is desirable to charge batteriesas rapidly as possible. At the same time, overchargingmust be limited to prolong battery life. Such limitation ofovercharging depends on factors such as the choice ofcharge termination technique and the use of multi-rate/multi-stage charging schemes. The majority of batterycharger ICs available today lock the user into one fixedcharging regimen, with at best a limited number ofcustomization options to suit a variety of application needsor battery types. The LTC®1325 addresses these shortcomingsby providing the user with all the functionalblocks needed to implement a simple but highly flexiblebattery charger (see Figure 1) which not only addressesthe issue of charging batteries but also those of batteryconditioning and capacity monitoring.
上傳時間: 2013-10-19
上傳用戶:royzhangsz
The design of battery-powered equipment can often bequite challenging. Since few ICs can operate directly fromthe end-of-life voltage from a 2-cell battery (about 1.8V),most systems require a DC/DCconverter. The systemdesigner often has a limited area in which to place the DC/DC converter; associated inductors and capacitors must be
上傳時間: 2013-11-23
上傳用戶:wys0120
為了改變目前電網現場作業管理的變電巡檢、變電檢修試驗、輸電線路巡檢檢修等管理系統各自獨立運行,信息不能共享,功能、效率受限,建設和維護成本高的現狀,提出了采用B/S+C/S構架模式,將各現場作業管理模塊和生產MIS(管理系統)集成為一體的現場作業管理系統的設計方案,做到各子系統和生產MIS軟硬資源共享,做到同一數據唯一入口、一處錄入多處使用。各子系統設備人員等基礎信息來源于生產管理系統,各子系統又是生產管理系統的作業數據、缺陷信息的重要來源。經過研究試用成功和推廣應用,目前該系統已在江西電網220 kV及以上變電站全面應用。 Abstract: In order to improve the status that the substation field inspection system, substation equipments maintenance and testing system, power-line inspection and maintenance system are running independent with each other. They can?蒺t share the resource information which accordingly constrains their functions and efficiency, and their construction and maintenance costs are high. This paper introduces a field standardized work management system based on B/S+C/S mode, integrating all field work management systems based on MIS and share the equipments and employee?蒺s data of MIS,the field work data of the sub systems are the source information of MIS, by which the same single data resouce with one-time input can be utilized in multiple places. After the research and testing, this system is triumphantly using in all 220kV and above substations in Jiangxi grid.
上傳時間: 2013-11-15
上傳用戶:han_zh
為解決直流逆變交流的問題,有效地利用能源,讓電源輸出最大功率,設計了高性能的基于IR2101最大功率跟蹤逆變器,并以SPMC75F2413A單片機作為主控制器。高電壓、高速功率的MOSFET或IGBT驅動器IR2101采用高度集成的電平轉換技術,同時上管采用外部自舉電容上電,能夠穩定高效地驅動MOS管。該逆變器可以實現DC/AC的轉換,最大功率點的跟蹤等功能。實際測試結果表明,該逆變器系統具有跟蹤能力強,穩定性高,反應靈敏等特點,該逆變器不僅可應用于普通的電源逆變系統,而且可應用于光伏并網發電的逆變系統,具有廣泛的市場前景。 Abstract: To solve the problem of DC-AC inverter, and to utilize solar energy more efficiently, the design of maximum power point tracking inverter based on IR2101 was achieved with a high-performance, which can make the system output power maximum. SPMC75F2413A was adopted as main controller. IR2101 is a high voltage, high speed power MOSFET and IGBT driver. It adopted highly integrated voltage level transforming technology, and an external bootstrap capacitor was used, which could drive MOS tube efficiently and stably. Many functions are achieved in the system, such as DC/AC conversion, maximun power point tracking, etc. The actual test result shows that the inverter system has characteristics of strong tracking ability, high stability and reacting quickly. The design can not only be used in ordinary power inverter system, but also be used in photovoltaic power inverter system. The design has certain marketing prospects
上傳時間: 2013-11-17
上傳用戶:lliuhhui
鎖定放大是微弱信號檢測的重要手段。基于相關檢測理論,利用開關電容的開關實現鎖定放大器中乘法器的功能,提出開關電容和積分器相結合以實現相關檢測的方法,并設計出一種鎖定放大器。該鎖定放大器將微弱信號轉化為與之相關的方波,通過后續電路得到正比于被測信號的直流電平,為后續采集處理提供方便。測量數據表明鎖定放大器前級可將10-6 A的電流轉換為10-1 V的電壓,后級通過帶通濾波器級聯可將信號放大1×105倍。該方法在降低噪聲的同時,可對微弱信號進行放大,線性度較高、穩定性較好。 Abstract: Lock-in Amplifying(LIA)is one of important means for weak signal detection. Based on cross-correlation detection theory, switch in the swithched capacitor was used as multiplier of LIA, and a new method of correlation detection was proposed combining swithched capacitor with integrator. A kind of LIA was designed which can convert the weak signal to square-wave, then DC proportional to measured signal was obtained through follow-up conditioning circuit, providing convenience for signal acquisition and processing. The measured data shows that the electric current(10-6 A) can be changed into voltage(10-1 V) by LIA, and the signal is magnified 1×105 times by cascade band-pass filter. The noise is suppressed and the weak signal is amplified. It has the advantages of good linearity and stability.
上傳時間: 2013-11-29
上傳用戶:黑漆漆