General Description The LM621 is a bipolar IC designed for commutation of brushless DC motors. The part is compatible with both three- and four-phase motors. It can directly drive the power switching devices used to drive the motor. The LM621 provides an adjustable dead-time circuit to eliminate ``shootthrough'' current spiking in the power switching circuitry. Operation is from a 5V supply, but output swings of up to 40V are accommodated. The part is packaged in an 18-pin, dual-in-line package.
上傳時間: 2013-07-24
上傳用戶:sdq_123
BGA布線指南 BGA CHIP PLACEMENT AND ROUTING RULE BGA是PCB上常用的組件,通常CPU、NORTH BRIDGE、SOUTH BRIDGE、AGP CHIP、CARD BUS CHIP…等,大多是以bga的型式包裝,簡言之,80﹪的高頻信號及特殊信號將會由這類型的package內拉出。因此,如何處理BGA package的走線,對重要信號會有很大的影響。 通常環繞在BGA附近的小零件,依重要性為優先級可分為幾類: 1. by pass。 2. clock終端RC電路。 3. damping(以串接電阻、排組型式出現;例如memory BUS信號) 4. EMI RC電路(以dampin、C、pull height型式出現;例如USB信號)。 5. 其它特殊電路(依不同的CHIP所加的特殊電路;例如CPU的感溫電路)。 6. 40mil以下小電源電路組(以C、L、R等型式出現;此種電路常出現在AGP CHIP or含AGP功能之CHIP附近,透過R、L分隔出不同的電源組)。 7. pull low R、C。 8. 一般小電路組(以R、C、Q、U等型式出現;無走線要求)。 9. pull height R、RP。 中文DOC,共5頁,圖文并茂
上傳時間: 2013-04-24
上傳用戶:cxy9698
MPC755 and MPC745 PowerPC microprocessors are high-performance, low-power, 32-bit implementations of
上傳時間: 2013-05-27
上傳用戶:330402686
FEATURES Unique 1-Wire interface requires only one port pin for communication Multidrop capability simplifies distributed temperature sensing applications Requires no external components Can be powered from data line. Power supply range is 3.0V to 5.5V Zero standby power required Measures temperatures from -55°C to +125°C. Fahrenheit equivalent is -67°F to +257°F ±0.5°C accuracy from -10°C to +85°C Thermometer resolution is programmable from 9 to 12 bits Converts 12-bit temperature to digital word in 750 ms (max.) User-definable, nonvolatile temperature alarm settings Alarm search command identifies and addresses devices whose temperature is outside of programmed limits (temperature alarm condition) Applications include thermostatic controls, industrial systems, consumer products, thermometers, or any thermally sensitive system
上傳時間: 2013-08-04
上傳用戶:CHENKAI
用fpga實現的DA轉換器,有說明和源碼,VDHL文件。\\r\\nA PLD Based Delta-Sigma DAC\\r\\nDelta-Sigma modulation is the simple, yet powerful,\\r\\ntechnique responsible for the extraordinary\\r\\nperformance and low cost of today s audio CD\\r\\nplayers. The simplest Delta-Sigm
上傳時間: 2013-08-22
上傳用戶:dudu1210004
protel 99se 使用技巧以及常見問題解決方法:里面有一些protel 99se 特別技巧,還有我們經常遇到的一些問題!如何使一條走線至兩個不同位置零件的距離相同? 您可先在Design/Rule/High Speed/Matched Net Lengths的規則中來新增規則設定,最后再用Tools/EqualizeNet Lengths 來等長化即可。 Q02、在SCHLIB中造一零件其PIN的屬性,如何決定是Passive, Input, I/O, Hi- Z,Power,…..?在HELP中能找到說明嗎?市面有關 SIM?PLD?的書嗎?或貴公司有講義? 你可在零件庫自制零件時點選零件Pin腳,并在Electrical Type里,可以自行設定PIN的 屬性,您可參考臺科大的Protel sch 99se 里面有介紹關于SIM的內容。 Q03、請問各位業界前輩,如何能順利讀取pcad8.6版的線路圖,煩請告知 Protel 99SE只能讀取P-CAD 2000的ASCII檔案格式,所以你必須先將P-CAD8.6版的格式轉為P-CAD 2000的檔案格式,才能讓Protel讀取。 Q04、請問我該如何標示線徑大小的那個平方呢 你可以將格點大小設小,還有將字形大小縮小,再放置數字的平方位置即可。 Q05、請問我一次如何更改所有組件的字型 您可以點選其中一個組件字型,再用Global的方法就可以達成你的要求。
上傳時間: 2013-10-22
上傳用戶:yd19890720
Q01、如何使一條走線至兩個不同位置零件的距離相同? 您可先在Design/Rule/High Speed/Matched Net Lengths的規則中來新增規則設定,最 后再用Tools/EqualizeNet Lengths 來等長化即可。 Q02、在SCHLIB中造一零件其PIN的屬性,如何決定是Passive, Input, I/O, Hi- Z,Power,…..?在HELP中能找到說明嗎?市面有關 SIM?PLD?的書嗎?或貴公司有講義? 你可在零件庫自制零件時點選零件Pin腳,并在Electrical Type里,可以自行設定PIN的 屬性,您可參考臺科大的Protel sch 99se 里 面有介紹關于SIM的內容。 Q03、請問各位業界前輩,如何能順利讀取pcad8.6版的線路圖,煩請告知 Protel 99SE只能讀取P-CAD 2000的ASCII檔案格式,所以你必須先將P-CAD8.6版的格式 轉為P-CAD 2000的檔案格式,才能讓Protel讀取。
標簽: Protel
上傳時間: 2013-11-22
上傳用戶:daxigua
Abstract: This application note describes how sampling clock jitter (time interval error or "TIE jitter") affectsthe performance of delta-sigma digital-to-analog converters (DACs). New insights explain the importanceof separately specifying low-frequency (< 2x passband frequency) and high-frequency or wideband (> 2xpassband frequency) jitter tolerance in these devices. The article also provides an application example ofa simple highly jittered cycle-skipped sampling clock and describes a method for generating a properbroadband jittered clock. The document then goes on to compare Maxim's audio DAC jitter tolerance tocompetitor audio DACs. Maxim's exceptionally high jitter tolerance allows very simple and low-cost sampleclock implementations.
上傳時間: 2013-10-25
上傳用戶:banyou
The MAX5713/MAX5714/MAX5715 4-channel, low-power,8-/10-/12-bit, voltage-output digital-to-analog converters(DACs) include output buffers and an internal referencethat is selectable to be 2.048V, 2.500V, or 4.096V. TheMAX5713/MAX5714/MAX5715 accept a wide supplyvoltage range of 2.7V to 5.5V with extremely low power(3mW) consumption to accommodate most low-voltageapplications. A precision external reference input allowsrail-to-rail operation and presents a 100kI (typ) load toan external reference.
上傳時間: 2013-12-23
上傳用戶:ArmKing88
The MAX4968/MAX4968A are 16-channel, high-linearity,high-voltage, bidirectional SPST analog switches with18I (typ) on-resistance. The devices are ideal for use inapplications requiring high-voltage switching controlledby a low-voltage control signal, such as ultrasound imagingand printers. The MAX4968A provides integrated40kI (typ) bleed resistors on each switch terminal todischarge capacitive loads. Using HVCMOS technology,these switches combine high-voltage bilateral MOSswitches and low-power CMOS logic to provide efficientcontrol of high-voltage analog signals.
上傳時間: 2013-10-09
上傳用戶:yepeng139