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.
標(biāo)簽： 開關(guān)穩(wěn)壓器 低噪聲 上傳時(shí)間： 2013-12-20
上傳用戶：ABCDE
XRP7714是一款四輸出脈寬調(diào)制（PWM）分級(jí)降壓（step down）DC-DC控制器，并具有內(nèi)置LDO提供待機(jī)電源。該器件在單個(gè)IC上為電池供電的產(chǎn)品提供了整套的電源管理方案，并且通過內(nèi)含的I2C串行接口進(jìn)行整體的編程配置。XRP7714器件的每一路輸出電壓的編程范圍是0.9V～5.1V，此范圍內(nèi)無需外部分壓器。可編程DPWM開關(guān)頻率的范圍從300kHz到1.5MHz，使用戶能夠在效率和元件大小之間取得最優(yōu)方案。為了讓用戶能夠在設(shè)計(jì)的多路電源XRP7714系統(tǒng)能夠取得最優(yōu)的方案，下文將詳細(xì)的介紹影響XRP7714系統(tǒng)效率的參數(shù)設(shè)置以及外圍器件的選型。
標(biāo)簽： 7714 XRP 多路電源 參數(shù)
上傳時(shí)間： 2013-10-31
上傳用戶：chendawei
產(chǎn)品特性2.4Ghz全球開放ISM頻段,免許可證使用最高工作速率1Mbps,高效GMSK調(diào)制,抗干擾能力強(qiáng),特別適合工業(yè)控制場(chǎng)合125頻道,滿足多點(diǎn)通信和跳頻通信需要內(nèi)置硬件CRC檢錯(cuò)和點(diǎn)對(duì)多點(diǎn)通信地址控制低功耗1.9~3.6V工作Power down模式下狀態(tài)僅為1uA內(nèi)置2.4Ghz天線,體積小巧約24x24mm不包括天線模塊可軟件設(shè)地址,只有收到本機(jī)地址時(shí)才會(huì)輸出數(shù)據(jù)(提供中斷指示,可直接接各種單片機(jī)使用,軟件編程非常方便內(nèi)置專門穩(wěn)壓電路,使用各種電源包括DC/DC開關(guān)電源均有很好的通信效果標(biāo)準(zhǔn)DIP間距接口便于嵌入式應(yīng)用PTR4000-Quick-DEV快速開發(fā)系統(tǒng),含開發(fā)板、源代碼、原理圖等詳細(xì)資料，即開即用，上手快，縮短您的開發(fā)時(shí)間
上傳時(shí)間： 2013-10-12
上傳用戶：sz_hjbf
MMC/SD卡以其優(yōu)越的性能，在單片機(jī)嵌入式設(shè)備中得到廣泛應(yīng)用。將MMC/SD卡作為外部掉電存儲(chǔ)介質(zhì)應(yīng)用于音頻信號(hào)發(fā)生器中，通過8051F330單片機(jī)上的SPI接口，實(shí)現(xiàn)單片機(jī)—MMC/SD卡的存儲(chǔ)擴(kuò)展，設(shè)計(jì)了此硬件平臺(tái)上的MMC/SD卡的單片機(jī)驅(qū)動(dòng)程序，并給出了相應(yīng)的程序代碼，滿足音頻信號(hào)發(fā)生器的大容量存儲(chǔ)要求。 Abstract: MMC/SD card is more and more widely used in the single chip embedded devices for their excellent performances.This article introduces the application of MMC/SD card as the external power down storage medium in audio signal generator. The extension technology especially for storage of single chip-MMC/SD card via SPI interfaces in 8051F330 single chip, including designs single chip drive program of MMC/SD card based on hardware platform,and also gives the key coding of the program. The implementation of big capacity storage is meaningful in audio signal generator.
標(biāo)簽： 8051F330 音頻信號(hào) 發(fā)生器
上傳時(shí)間： 2014-12-27
上傳用戶：黃華強(qiáng)
FEATURES400 MSPS internal clock speedIntegrated 10-bit DAC32-bit tuning wordPhase noise ≤ –120 dBc/Hz @ 1 kHz offset (DAC output)Excellent dynamic performance>75 dB SFDR @ 160 MHz (±100 kHz offset) AOUTSerial I/O control1.8 V power supplySoftware and hardware controlled power-down48-lead TQFP/EP packageSupport for 5 V input levels on most digital inputsPLL REFCLK multiplier (4× to 20×)Internal oscillator; can be driven by a single crystalPhase modulation capabilityMultichip synchronization
上傳時(shí)間： 2014-12-04
上傳用戶：axin881314
Features• Complete DTMF Receiver• Low power consumption• Internal gain setting amplifier• Adjustable guard time• Central office quality• Power-down mode• Inhibit mode• Backward compatible withMT8870C/MT8870C-1Applications• Receiver system for British Telecom (BT) orCEPT Spec (MT8870D-1)• Paging systems• Repeater systems/mobile radio• Credit card systems• Remote control• Personal computers• Telephone answering machine
上傳時(shí)間： 2013-11-20
上傳用戶：mpquest
Virtex-5, Spartan-DSP FPGAs Application Note This application note demonstrates how efficient implementations of Digital Up Converters(DUC) and Digital down Converters (DDC) can be done by leveraging the Xilinx DSP IPportfolio for increased productivity and reduced time to development. Step-by-step instruction is given on how to perform system-level trade off analysis and develop the most efficient FPGA implementation, thus allowing engineers a flexible, low-cost and low-power alternative to ASSP technologies.
標(biāo)簽： Spartan-DSP Virtex FPGAs Ap
上傳時(shí)間： 2013-10-23
上傳用戶：raron1989
The CAT28LV64 is a low voltage, low power, CMOS Parallel EEPROM organized as 8K x 8−bits. It requires a simple interface for in−system programming. On−chip address and data latches, self−timed write cycle with auto−clear and VCC power up/down write protection eliminate additional timing and protection hardware. DATA Polling and Toggle status bit signal the start and end of the self−timed write cycle. Additionally, the CAT28LV64 features hardware and software write protection.
上傳時(shí)間： 2013-11-16
上傳用戶：浩子GG
CAT5110/18/19/23/24/25 linear-taper digitally programmable potentiometers perform the same function as a mechanical potentiometer or a variable resistor. These devices consist of a fixed resistor and a wiper contact with 32-tap points that are digitally controlled through a2-wire up/down serial interface.
上傳時(shí)間： 2013-11-22
上傳用戶：541657925
MC9S08QG8英文資料 The MC9S08QG8 is the newest member of the Freescale 8-bit family of highly integratedmicrocontrollers, based on the high-performance yet low power HCS08 core. The MC9S08QG8is an excellent solution for power-sensitive applications with extended battery life and maximum performance down to 1.8VDC.
上傳時(shí)間： 2014-12-28
上傳用戶：dxxx
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