PW2330 develops a high efficiency synchronous step down DC-DC converter capable of delivering3A output current. PW2330 operates over a wide input voltage range from 4.5V to 30V andintegrates main switch and synchronous switch with very low RDS(ON) to minimize the conductionloss. PW2330 adopts the proprietary instant PWM architecture to achieve fast transient responsesfor high step down applications and high efficiency at light loads. In addition, it operates atpseudo-constant frequency of 500kHz under continuous conduction mode to minimize the size ofinductor and capacitor
標(biāo)簽： pw2330
上傳時(shí)間： 2022-02-11
上傳用戶：
The PW2312 is a high frequency, synchronous, rectified, step-down, switch-mode converter withinternal power MOSFETs. It offers a very compact solution to achieve a 1.5A peak output currentover a wide input supply range, with excellent load and line regulation.The PW2312 requires a minimal number of readily available, external components and is available ina space saving SOT23-6 package.
標(biāo)簽： pw2312
上傳時(shí)間： 2022-02-11
上傳用戶：qingfengchizhu
The PW2228A is a high efficiency single inductor Buck-Boost converter which can supply theload current up to 1.5A. It provides auto-transition between Buck and Boost Mode. The PW2228Aoperates at 2.4MHz switching frequency in CCM. DC/DC converter operates at Pulse-Skipping Modeat light load. The output voltage is programmable using an external resistor divider, or is fixed to3.3V internally. The load is disconnected from the VIN during shutdown.The PW2228A is available in TDFN3X3-10 package.
標(biāo)簽： pw2228a
上傳時(shí)間： 2022-02-11
上傳用戶：
PW2205 develops a high efficiency synchronous step-down DC-DC converter capable of delivering5A output current. PW2205 operates over a wide input voltage range from 4.5V to 30V andintegrates main switch and synchronous switch with very low RDS(ON) to minimize the conductionloss.PW2205 adopts the instant PWM architecture to achieve fast transient responses for high step downapplications and high efficiency at light loads. In addition, it operates at pseudo-constant frequencyof 500kHz under continuous conduction mode to minimize the size of inductor and capacitor
標(biāo)簽： pw2205
上傳時(shí)間： 2022-02-11
上傳用戶：
The PW2163D is a high frequency, synchronous, rectified, step-down, switch-mode converter withinternal powerMOSFETs. It offers a very compact solution to provide a 3A continuous current over awide input supply range,with excellent load and line regulation.The PW2163D requires a minimal number of readily available, external components and is availablein a spacesaving SOT23-6 package
標(biāo)簽： pw2163d
上傳時(shí)間： 2022-02-11
上傳用戶：
The PW2163 is a high efficiency 500 kHz synchronous step-down DC-DC converter capable ofdelivering 3A current. The PW2163 operates over a wide input voltage range from 4.5V to 18V andintegrates main switch and synchronous switch with very low RDS(ON) to minimize the conductionloss. Low output voltage ripple and small external inductor and capacitor sizes are achieved with 500kHz switching frequency. It adopts the instant PWM architecture to achieve fast transient responsesfor high step down applications
標(biāo)簽： pw2163
上傳時(shí)間： 2022-02-11
上傳用戶：
The PW2053 is a high-efficiency monolithic synchronous buck regulator using a constantfrequency, current mode architecture. The device is available in an adjustable version. Supply currentwith no load is 40uA and drops to <1uA in shutdown. The 2.5V to 5.5V input voltage range makesthe PW2053 ideally suited for single Li-Ion battery powered applications. 100% duty cycle provideslow dropout operation, extending battery life in portable systems. PWM/PFM mode operationprovides very low output ripple voltage for noise sensitive applications. Switching frequency isinternally set at 1.2MHz, allowing the use of small surface mount inductors and capacitors. Lowoutput voltages are easily supported with the 0.6V feedback reference voltage
標(biāo)簽： pw2053
上傳時(shí)間： 2022-02-14
上傳用戶：jason_vip1
5G通信系統(tǒng)中massive-MIMO-FBMC技術(shù)的結(jié)合概述摘要為了應(yīng)對第五代移動通信（5G）中更高數(shù)據(jù)率和更低時(shí)延的需求，大規(guī)模MIMO （massive multiple-input multiple-output）技術(shù)已經(jīng)被提出并被廣泛研究。大規(guī)模 MIMO技術(shù)能大幅度地提升多用戶網(wǎng)絡(luò)的容量。而在5G中的帶寬研究方面，特別 是針對碎片頻譜和頻譜靈活性問題，現(xiàn)有的正交頻分多址（Orthogonal Frequency Division Multiplexing, OFDM）技術(shù)不可能應(yīng)對未來的挑戰(zhàn)，新的波形方案需要 被設(shè)計(jì)出來。基于此，F(xiàn)BMC（filter bank multicarrier）技術(shù)由于具有比OFDM低 得多的帶外頻譜泄露而被受到重視，并已被標(biāo)準(zhǔn)推進(jìn)組IMT-2020列為5G物理層 的主要備選方案之一。 本文首先回顧了5G中波形設(shè)計(jì)方案（主要是FBMC調(diào)制）和大規(guī)模多天線系 統(tǒng)（即massive MIMO）的現(xiàn)有工作和主要挑戰(zhàn)。然后，簡要介紹了基于Massive MIMO的FBMC系統(tǒng)中的自均衡性質(zhì)，該性質(zhì)可以用于減少系統(tǒng)所需的子載波數(shù) 目。同時(shí)，F(xiàn)BMC中的盲信道跟蹤性質(zhì)可以用于消除massive MIMO系統(tǒng)中的導(dǎo)頻 污染問題。盡管如此，如何將FBMC技術(shù)應(yīng)用于massive MIMO系統(tǒng)中的誤碼率、 計(jì)算復(fù)雜度、線性需求等方面仍然不明確，未來更多的研究工作需要在massive MIMO-FBMC方面展開來。 關(guān)鍵詞：大規(guī)模MIMO；FBMC；自均衡；導(dǎo)頻污染；盲均衡
標(biāo)簽： 5G 通信系統(tǒng)
上傳時(shí)間： 2022-02-25
上傳用戶：
隨著光通信的蓬勃發(fā)展，光纖通信技術(shù)廣泛應(yīng)用于電信、電力、廣播等領(lǐng)域，對整個(gè)信息產(chǎn)業(yè)產(chǎn)生了深遠(yuǎn)影響，光纖已成為當(dāng)前最有前景的傳輸媒介。與此同時(shí)，光纖測試技術(shù)在光纖生產(chǎn)、現(xiàn)場鋪設(shè)與后期維護(hù)等工程領(lǐng)域中得到廣泛應(yīng)用。光時(shí)域反射儀（Optical Time Domain Reflectometer），又稱背向散射儀，是一種用于表征光纖鏈路物理特性的精密光學(xué)測試儀器，主要用于測試光纖鏈路長度，精確定位斷點(diǎn)事件，計(jì)算光纖損耗，并提供與長度有關(guān)的衰減細(xì)節(jié)。光纖鏈路中待測光纖的測量長度范圍和測量精度，取決于OTDR的激光出纖功率和光脈寬。因此，需要設(shè)計(jì)合適的激光脈沖驅(qū)動電源及配套的控制和探測系統(tǒng)，研究激光出纖功率和脈寬對測量長度和測量精度的影響，從而獲得能滿足不同光纖鏈路測量需求的OTDR系統(tǒng)解決方案。文章在具體描述了光時(shí)域反射儀的工作機(jī)理以及影響其主要性能的關(guān)鍵參數(shù)的基礎(chǔ)上，提出以設(shè)計(jì)能提供大功率、窄脈沖電流信號的激光驅(qū)動電源作為提高OTDR性能的主要手段。在掌握半導(dǎo)體激光驅(qū)動原理的基礎(chǔ)上，經(jīng)過細(xì)致地比較與方案論證提出以 MOSFET作為激光脈沖驅(qū)動電源的開關(guān)器件，以能量儲存法作為窄脈沖產(chǎn)生機(jī)制的脈沖電源設(shè)計(jì)方案，設(shè)計(jì)實(shí)現(xiàn)基于FPGA的觸發(fā)脈沖信號，并通過 Multisim對系統(tǒng)硬件電路仿真優(yōu)化，實(shí)現(xiàn)激光脈沖驅(qū)動大功率、窄脈寬輸出。以雪崩二極管作為光電探測系統(tǒng)關(guān)鍵響應(yīng)轉(zhuǎn)換器件驗(yàn)證驅(qū)動電源性能，并完成光纖測距。最終成功研制出一套基于納秒脈沖激光和對應(yīng)光電探測系統(tǒng)的OTDR系統(tǒng)，并進(jìn)行了實(shí)際測試測試和研究結(jié)果顯示：所研制的脈沖激光電源能輸出的最小脈寬為33n，最小輸出峰值電流為1A，且峰值電流及頻率大小可調(diào)。大電流窄脈寬驅(qū)動電源信號輸出可極大地增強(qiáng)光時(shí)域反射儀的動態(tài)范圍以及分辨率，探測器分時(shí)調(diào)控測量技術(shù)可以極大地提高系統(tǒng)的測量精度和信噪比。
上傳時(shí)間： 2022-03-11
上傳用戶：
本系統(tǒng)采用電動機(jī)電樞供電回路串接采樣電阻的方式來實(shí)現(xiàn)對小型直流有刷電動機(jī)的轉(zhuǎn)速測量。該系統(tǒng)主要由二階低通濾波電路,小信號放大電路、單片機(jī)測量顯示電路、開關(guān)穩(wěn)壓電源電路等組成。同時(shí)自制電機(jī)測速裝置,用高頻磁環(huán)作為載體,用線圈繞制磁環(huán),利用電磁感應(yīng)原理檢測電機(jī)運(yùn)行時(shí)的漏磁,將變化的磁場信號轉(zhuǎn)化為磁環(huán)上的感應(yīng)電流。用信號處理單元電路將微弱電信號轉(zhuǎn)化為脈沖信號,送由單片機(jī)檢測,從而達(dá)到準(zhǔn)確測量電機(jī)的速度的要求。In this system, the sampling resistance of armature power supply circuit is connected in series to measure the speed of small DC brush motor. The system is mainly composed of second-order low-pass filter circuit, small signal amplifier circuit, single-chip measurement and display circuit, switching regulated power supply circuit and so on. At the same time, the self-made motor speed measuring device uses high frequency magnetic ring as the carrier, coil winding magnetic ring, and electromagnetic induction principle to detect the leakage of magnetic field during the operation of the motor, which converts the changed magnetic field signal into the induced current on the magnetic ring. The weak electric signal is transformed into pulse signal by signal processing unit circuit, which is sent to single chip computer for detection, so as to meet the requirement of accurate measurement of motor speed.
標(biāo)簽： 直流電動機(jī)
上傳時(shí)間： 2022-03-26
上傳用戶：
蟲蟲下載站版權(quán)所有 京ICP備2021023401號-1
