The purpose of this application note is to show an example of how a digital potentiometer can be used in thefeedback loop of a step-up DC-DC converter to provide calibration and/or adjustment of the output voltage.The example circuit uses a MAX5025 step-up DC-DC converter (capable of generating up to 36V,120mWmax) in conjunction with a DS1845, 256 position, NV digital potentiometer. For this example, the desiredoutput voltage is 32V, which is generated from an input supply of 5V. The output voltage can be adjusted in35mV increments (near 32V) and span a range wide enough to account for resistance, potentiometer and DCDCconverter tolerances (27.6V to 36.7V).
標(biāo)簽: DC-DC 數(shù)字電位器 升壓型 校準(zhǔn)
上傳時間: 2014-12-23
上傳用戶:781354052
凌力爾特公司提供了一個規(guī)模龐大且不斷成長的高電壓 DC/DC 轉(zhuǎn)換器繫列,這些器件是專為驅(qū)動高功率 LED 而設(shè)計的。
標(biāo)簽: LED 高電壓 降壓型轉(zhuǎn)換器 驅(qū)動高功率
上傳時間: 2013-11-12
上傳用戶:playboys0
對於許多電子子繫統(tǒng)而言,比如:VFD (真空熒光顯示屏)、TFT-LCD、GPS 或 DSL 應(yīng)用,僅采用一個簡單的降壓或升壓型 DC/DC 轉(zhuǎn)換器並不能滿足其要求
上傳時間: 2014-12-24
上傳用戶:nostopper
對於輸出電壓處於輸入電壓範(fàn)圍之內(nèi) (這在鋰離子電池供電型應(yīng)用中是一種很常見的情形) 的 DC/DC 轉(zhuǎn)換器設(shè)計,可供采用的傳統(tǒng)解決方案雖有不少,但迄今為止都不能令人非常滿意
上傳時間: 2013-11-19
上傳用戶:urgdil
Abstract: The DS1875 features a pulse-width modulation (PWM) controller that can be used to control aDC-DC converter. The DC-DC converter can then be used to generate the high bias voltages necessaryfor avalanche photodiodes (APDs). This application note describes the operation of a boost converterthat uses the DS1875. Discussion covers the selection of the inductor and switching frequency, and theselection of components that improve the efficiency of the converter. Test data are presented.
標(biāo)簽: DC-DC 如何設(shè)計 高效率 轉(zhuǎn)換器
上傳時間: 2013-10-26
上傳用戶:lyson
便攜式電子器件(如智能手機、GPS導(dǎo)航系統(tǒng)和平板電腦)的電源可以來自低壓太陽能電池板、電池或AC/DC電源。電池供電系統(tǒng)通常將電池串聯(lián)疊置以實現(xiàn)更高的電壓,但由于空間不足,此技術(shù)未必總是可行。開關(guān)轉(zhuǎn)換器使用電感的磁場來交替地存儲電能,并以不同電壓釋放至負(fù)載。因為損耗很低,所以開關(guān)轉(zhuǎn)換器是個不錯的高效率選擇。連接至轉(zhuǎn)換器輸出端的電容可減少輸出電壓紋波。升壓轉(zhuǎn)換器提供較高的輸出電壓;而應(yīng)用筆記AN-1125(如何運用DC-DC降壓調(diào)節(jié)器)所討論的降壓轉(zhuǎn)換器則提供較低的輸出電壓。內(nèi)置FET作為開關(guān)的開關(guān)轉(zhuǎn)換器稱為開關(guān)調(diào)節(jié)器,需要外部FET的開關(guān)轉(zhuǎn)換器則稱為開關(guān)控制器。
標(biāo)簽: DC-DC 如何運用 升壓調(diào)節(jié)器
上傳時間: 2013-11-04
上傳用戶:edisonfather
A number of conventional solutions have been available forthe design of a DC/DC converter where the output voltageis within the input voltage range—a common scenarioin Li-Ion battery-powered applications—but none werevery attractive until now. Conventional topologies, suchas SEPIC or boost followed by buck, have numerousdisadvantages, including low effi ciency, complex magnetics,polarity inversion and/or circuit complexity/cost. TheLTC®3785 buck-boost controller yields a simple, effi cient,low parts-count, single-converter solution that is easyto implement, thus avoiding the drawbacks associatedwith traditional solutions.
上傳時間: 2013-10-21
上傳用戶:ljt101007
說明:單排直插(SIP)封裝或雙排直插DIP(封裝),任意值電壓輸入轉(zhuǎn)換出任意值電壓輸出,精度為±2%或±3%.簡說:DC/DC定電壓隔離雙隔離(輸入/輸出隔離、兩路輸出之間也隔離,雙輸出,兩路正壓或兩路負(fù)壓及或一正一負(fù))轉(zhuǎn)換器,輸出共同一地線,瞬變響應(yīng)快,極低紋波噪聲輸出,無需任何外圍元件即可工作,腳位采用7PIN單列,14PIN雙列直插,小型封裝。應(yīng)用:便攜儀表,醫(yī)學(xué)儀表,自控裝置,防盜報警器,手持儀表,通訊設(shè)備等數(shù)字電路。
標(biāo)簽: DC-DC 模塊 電源應(yīng)用
上傳時間: 2013-10-31
上傳用戶:qq527891923
針對目前使用的RS232接口數(shù)字化B超鍵盤存在PC主機啟動時不能設(shè)置BIOS,提出一種PS2鍵盤的設(shè)計方法。基于W78E052D單片機,采用8通道串行A/D轉(zhuǎn)換器設(shè)計了8個TGC電位器信息采集電路,電位器位置信息以鍵盤掃描碼序列形式發(fā)送,正交編碼器信號通過XC9536XL轉(zhuǎn)換為單片機可接收的中斷信號,軟件接收到中斷信息后等效處理成按鍵。結(jié)果表明,在滿足開機可設(shè)置BIOS同時,又可實現(xiàn)超聲特有功能,不需要專門設(shè)計驅(qū)動程序,接口簡單,成本低。 Abstract: Aiming at the problem of the digital ultrasonic diagnostic imaging system keyboard with RS232 interface currently used couldn?蒺t set the BIOS when the PC boot, this paper proposed a design method of PS2 keyboards. Based on W78E052D microcontroller,designed eight TGC potentiometers information acquisition circuit with 8-channel serial A/D converter, potentiometer position information sent out with keyboard scan code sequentially.The control circuit based on XC9536 CPLD is used for converting the mechanical actions of the encoders into the signals that can be identified by the MCU, software received interrupt information and equivalently treatmented as key. The results show that the BIOS can be set to meet the boot, ultrasound specific functionality can be achieved at the same time, it does not require specially designed driver,the interface is simple and low cost.
標(biāo)簽: 單片機 B超 數(shù)字化 鍵盤設(shè)計
上傳時間: 2013-10-10
上傳用戶:asdfasdfd
82C55A是高性能,工業(yè)標(biāo)準(zhǔn),并行I/O的LSI外圍芯片;提供24條I/O腳線。 在三種主要的操作方式下分組進行程序設(shè)計82C88A的幾個特點:(1)與所有Intel系列微處理器兼容;(2)有較高的操作速度;(3)24條可編程I/O腳線;(4)底功耗的CHMOS;(5)與TTL兼容;(6)擁有控制字讀回功能;(7)擁有直接置位/復(fù)位功能;(8)在所有I/O輸出端口有2.5mA DC驅(qū)動能力;(9)適應(yīng)性強。方式0操作稱為簡單I/O操作,是指端口的信號線可工作在電平敏感輸入方式或鎖存輸出。所以,須將控制寄存器設(shè)計為:控制寄存器中:D7=1; D6 D5=00; D2=0。D7位為1代表一個有效的方式。通過對D4 D3 D1和D0的置位/復(fù)位來實現(xiàn)端口A及端口B是輸入或輸出。P56表2-1列出了操作方式0端口管腳功能。
上傳時間: 2013-10-26
上傳用戶:brilliantchen
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