Wirelesscommunications,especiallyinitsmobileform,hasbroughtusthefreedomofmobility andhaschangedthelifestylesofmodernpeople.Waitingatafixedlocationtoreceiveormakea phone call, or sitting in front of a personal computer to send an e-mail or download a video program, has become an old story. Nowadays it is commonplace for people to talk over a cell phonewhilewalkingonthestreet,ortodownloadandwatchamoviewhiletravelingonatrain. Thisisthebenefitmadeavailabletousbythesuccessfulevolutionofwirelesscommunications over three generations, with the fourth generation being under way.
標(biāo)簽： Communications Management Wireless Resource
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
Introduction to Radio Frequency Identification (RFID): RFID is a wireless modulation and demodulation technique for automatic identification of objects, tracking goods, smart logistics, and access con- trol. RFID is a contactless, usually short‐distance transmission and reception technique for unique ID data transfer from a tagged object to an interrogator (reader). The generic configuration of an RFID system comprises (i) an ID data‐carrying tag, (ii) a reader, (iii) a middleware, and (iv) an enterprise application.
標(biāo)簽： Chipless_Radio_Frequency_Identifi cation
上傳時(shí)間： 2020-06-08
上傳用戶：shancjb
ROHM最近推出了SiCMOSFET的新系列產(chǎn)品“SCT3xxxxR系列”。SCT3xxxxR系列采用最新的溝槽柵極結(jié)構(gòu)，進(jìn)一步降低了導(dǎo)通電阻；同時(shí)通過(guò)采用單獨(dú)設(shè)置柵極驅(qū)動(dòng)器用源極引腳的4引腳封裝，改善了開(kāi)關(guān)特性，使開(kāi)關(guān)損耗可以降低35%左右。此次，針對(duì)SiCMOSFET采用4引腳封裝的原因及其效果等議題，我們采訪了ROHM株式會(huì)社的應(yīng)用工程師。關(guān)于SiCMOSFET的SCT3xxxxR系列，除了導(dǎo)通電阻很低，還通過(guò)采用4引腳封裝使開(kāi)關(guān)損耗降低了35%，對(duì)此我們非常感興趣。此次，想請(qǐng)您以4引腳封裝為重點(diǎn)介紹一下該產(chǎn)品。首先，請(qǐng)您大致講一下4引腳封裝具體是怎樣的封裝，采用這種封裝的背景和目的是什么。首先，采用4引腳封裝是為了改善SiCMOSFET的開(kāi)關(guān)損耗。包括SiCMOSFET在內(nèi)的電源開(kāi)關(guān)用MOSFET和IGBT，被作為開(kāi)關(guān)元件廣泛應(yīng)用于各種電源應(yīng)用和電源線路中。必須盡可能地降低這種開(kāi)關(guān)元件產(chǎn)生的開(kāi)關(guān)損耗和傳導(dǎo)損耗，但不同的應(yīng)用，其降低損耗的方法也不盡相同。作為其中的一種手法，近年來(lái)發(fā)布了一種4引腳的新型封裝，即在MOSFET的源極、漏極、柵極三個(gè)引腳之外，另外設(shè)置了驅(qū)動(dòng)器源極引腳。此次的SCT3xxxxR系列，旨在通過(guò)采用最新的溝槽柵極結(jié)構(gòu)，實(shí)現(xiàn)更低的導(dǎo)通電阻和傳導(dǎo)損耗；通過(guò)采用4引腳封裝，進(jìn)一步發(fā)揮出SiC本身具有的高速開(kāi)關(guān)性能，并降低開(kāi)關(guān)損耗。那么，我想詳細(xì)了解一下剛剛您的概述中出現(xiàn)的幾個(gè)要點(diǎn)。首先，什么是“驅(qū)動(dòng)器源極引腳”？驅(qū)動(dòng)器源極引腳是應(yīng)用了開(kāi)爾文連接原理的源極引腳。開(kāi)爾文連接是通過(guò)電阻測(cè)量中的4個(gè)引腳或四線檢測(cè)方式，在電流路徑基礎(chǔ)上加上兩條測(cè)量電壓的線路，以極力消除微小電阻測(cè)量或大電流條件下測(cè)量時(shí)不可忽略的線纜電阻和接觸電阻的影響的方法，是一種廣為人知的方法。這種4引腳封裝僅限源極，通過(guò)使連接?xùn)艠O驅(qū)動(dòng)電路返回線的源極電壓引腳與流過(guò)大電流的電源源極引腳獨(dú)立，來(lái)消除ID對(duì)柵極驅(qū)動(dòng)電路的影響。
上傳時(shí)間： 2021-11-07
上傳用戶：
The PW4554 is a cost-effective, fully integrated high input voltage single-cell Li-ion battery charger.The charger uses a CC/CV charge profile required by Li-ion battery. The charger accepts an inputvoltage up to 24V but is disabled when the input voltage exceeds the OVP threshold, typically 6.8V,to prevent excessive power dissipation. The 24V rating eliminates the over-voltage protection circuitrequired in a low input voltage charger
標(biāo)簽： pw4554
上傳時(shí)間： 2022-02-11
上傳用戶：
PW4203 is a 4.5-22V input, 2A multi-cell synchronous Buck Li-Ion battery charger, suitable forportable application. Select pin is convenient for multi-cell charging. 800 kHz synchronous buckregulator integrates of 22V rating FETs with ultra low on- resistance to achieve high efficiency andsimple circuit design.The PW4203 is available in an 8-pin SOP package, provides a very compact system solution andgood thermal conductance
標(biāo)簽： pw4203
上傳時(shí)間： 2022-02-11
上傳用戶：
The PW4055 is a complete constant-current /constant-voltage linear charger for single cell lithiumion batteries.Its ThinSOT package and low external component count make the PW4055 ideallysuited for portable applications.Furthermore, the PW4055 is specifically designed to work within USBpower specifications.The PW4055 No external sense resistor is needed, and no blocking diode is required due to theinternal MOSFET architecture.Thermal feedback regulates the charge current to limit the dietemperature during high power operation or high ambient temperature. The charge voltage is fixedat 4.2V, and the charge current can be programmed externally with a single resistor. The PW4055automatically terminates the charge cycle when the charge current drops to 1/10th the programmedvalue after the final float voltage is reached. When the input supply (wall adapter or USB supply) isremoved, the PW4055 automatically enters a low current state, dropping the battery drain currentto less than 2μA. The PW4055 can be put into shutdown mode, reducing the supply current to 25μA.The BAT pin has a 7KV ESD(HBM) capability. Other features include charge current monitor, undervoltage lockout, automatic recharge and a status pin to indicate charge termination and the presenceof an input voltage
標(biāo)簽： pw4055
上傳時(shí)間： 2022-02-11
上傳用戶：jason_vip1
The PW3130 series product is a high integration solution for lithium-lion/polymer batteryprotection.PW3130 contains advanced power MOSFET, high-accuracy voltage detection circuits anddelay circuits. PW3130 is put into an ultra-small SOT23-5 package and only one external componentmakes it an ideal solution in limited space of battery pack. PW3130 has all the protection functionsrequired in the battery application including overcharging, overdischarging, overcurrent and loadshort circuiting protection etc. The accurate overcharging detection voltage ensures safe and fullutilization charging.The low standby current drains little current from the cell while in storage. Thedevice is not only targeted for digital cellular phones, but also for any other Li-Ion and Li-Polybattery-powered information appliances requiring long-term battery life
標(biāo)簽： pw3130
上傳時(shí)間： 2022-02-11
上傳用戶：fliang
The PW2301A uses advanced trench It utilizes the latest processing techniques to achieve the highcell density and reduces the on-resistance with high repetitive avalanche rating. These featurescombine to make this design an extremely efficient and reliable device for use in power switchingapplication and a wide variety of other applications
標(biāo)簽： pw2301a
上傳時(shí)間： 2022-02-11
上傳用戶：
The PW8205A8TS is the highest performance trench N-ch MOSFETs with extreme high cell density,which provide excellent RDSON and gate charge for most of the small power switching and loadswitch applications. The meet the RoHS and Product requirement with full function reliabilityapproved .
標(biāo)簽： 8205a8
上傳時(shí)間： 2022-02-14
上傳用戶：wangshoupeng199
5G通信技術(shù)白皮書(shū)技術(shù)資料合集摘 要 5G 致力于應(yīng)對(duì) 2020 后多樣化差異化業(yè)務(wù)的巨大挑戰(zhàn)，滿足超高速率、超低時(shí)延、高速移動(dòng)、高能效 和超高流量與連接數(shù)密度等多維能力指標(biāo)。FuTURE 論壇 5G 特別興趣組（SIG）圍繞著“柔性、綠色、極 速”的 5G 愿景，以“5+2”技術(shù)理念，重新思考 5G 網(wǎng)絡(luò)的設(shè)計(jì)原則： 1) 香農(nóng)理論再思考（Rethink Shannon）：為無(wú)線通信系統(tǒng)開(kāi)啟綠色之旅 2) 蜂窩再思考（Rethink Ring & Young）：蜂窩不再（no more cell） 3) 信令控制再思考（Rethink signaling & control）：讓網(wǎng)絡(luò)更智能 4) 天線再思考（Rethink antennas）：通過(guò) SmarTIle 讓基站隱形 5) 頻譜空口再思考（Rethink spectrum & air interface）：
標(biāo)簽： 5G通信
上傳時(shí)間： 2022-03-06
上傳用戶：
蟲(chóng)蟲(chóng)下載站版權(quán)所有 京ICP備2021023401號(hào)-1
