本次在線座談主要介紹TI的高精度Delta-Sigma A/D轉換器的原理及其應用,Delta-Sigma A/D轉換器在稱重儀器中,大量采用比例測量方法。
標簽: Delta-Sigma 高精度 轉換器
上傳時間: 2013-10-17
上傳用戶:zhqzal1014
Differential Nonlinearity: Ideally, any two adjacent digitalcodes correspond to output analog voltages that are exactlyone LSB apart. Differential non-linearity is a measure of theworst case deviation from the ideal 1 LSB step. For example,a DAC with a 1.5 LSB output change for a 1 LSB digital codechange exhibits 1⁄2 LSB differential non-linearity. Differentialnon-linearity may be expressed in fractional bits or as a percentageof full scale. A differential non-linearity greater than1 LSB will lead to a non-monotonic transfer function in aDAC.Gain Error (Full Scale Error): The difference between theoutput voltage (or current) with full scale input code and theideal voltage (or current) that should exist with a full scale inputcode.Gain Temperature Coefficient (Full Scale TemperatureCoefficient): Change in gain error divided by change in temperature.Usually expressed in parts per million per degreeCelsius (ppm/°C).Integral Nonlinearity (Linearity Error): Worst case deviationfrom the line between the endpoints (zero and full scale).Can be expressed as a percentage of full scale or in fractionof an LSB.LSB (Lease-Significant Bit): In a binary coded system thisis the bit that carries the smallest value or weight. Its value isthe full scale voltage (or current) divided by 2n, where n is theresolution of the converter.Monotonicity: A monotonic function has a slope whose signdoes not change. A monotonic DAC has an output thatchanges in the same direction (or remains constant) for eachincrease in the input code. the converse is true for decreasing codes.
標簽: Converters Defini DAC
上傳時間: 2013-10-30
上傳用戶:stvnash
ANALOG INPUT BANDWIDTH is a measure of the frequencyat which the reconstructed output fundamental drops3 dB below its low frequency value for a full scale input. Thetest is performed with fIN equal to 100 kHz plus integer multiplesof fCLK. The input frequency at which the output is −3dB relative to the low frequency input signal is the full powerbandwidth.APERTURE JITTER is the variation in aperture delay fromsample to sample. Aperture jitter shows up as input noise.APERTURE DELAY See Sampling Delay.BOTTOM OFFSET is the difference between the input voltagethat just causes the output code to transition to the firstcode and the negative reference voltage. Bottom Offset isdefined as EOB = VZT–VRB, where VZT is the first code transitioninput voltage and VRB is the lower reference voltage.Note that this is different from the normal Zero Scale Error.CONVERSION LATENCY See PIPELINE DELAY.CONVERSION TIME is the time required for a completemeasurement by an analog-to-digital converter. Since theConversion Time does not include acquisition time, multiplexerset up time, or other elements of a complete conversioncycle, the conversion time may be less than theThroughput Time.DC COMMON-MODE ERROR is a specification which appliesto ADCs with differential inputs. It is the change in theoutput code that occurs when the analog voltages on the twoinputs are changed by an equal amount. It is usually expressed in LSBs.
上傳時間: 2013-11-12
上傳用戶:pans0ul
基于MDK RTX 的COrtex—M3 多任務應用設計 武漢理工大學 方安平 武永誼 摘要:本文描述了如何在Cortex—M3 上使用MDK RL—RTX 的方法,并給出了一個簡單的多任務應用設計。 關鍵詞:MDK RTX,Cortex,嵌入式,ARM, STM32F103VB 1 MDK RL—RTX 和COrtex—M3 概述 MDK 開發套件源自德國Keil 公司,是ARM 公司目前最新推出的針對各種嵌入式處理器 的軟件開發工具。MDKRL—IUX 是一個實時操作系統(RTOS)內核,完全集成在MDK 編譯器中。廣泛應用于ARM7、ARM9 和Cortex-M3 設備中。它可以靈活解決多任務調度、維護和時序安排等問題。基于RL—I 訂X 的程序由標準的C 語言編寫,由Real—View 編譯器進行編譯。操作系統依附于C 語言使聲明函數更容易,不需要復雜的堆棧和變量結構配置,大大簡化了復雜的軟件設計,縮短了項目開發周期。
上傳時間: 2014-12-23
上傳用戶:Yue Zhong
cv181l-a-20
標簽: Specification_V 181 1.0 L-A
上傳時間: 2013-11-14
上傳用戶:daijun20803
TI 的 Stellaris 系列是行業中領先的產品系列,其可靠的實時微控制器 (MCU) 以 ARM 革命性的 Cortex-M3 技術為基礎。根據對系統的限制,如電池操作、成本要求或對高效率的需求,TI 提供最佳的產品為使用 Stellaris MCU 的系統提供支持。
標簽: Stellaris Cortex-M ARM MCU
上傳時間: 2013-10-12
上傳用戶:hgmmyl
基于嵌入式實時操作系統的OBD-II診斷協議框架,以Cortex-M3為內核,采用uc/os II操作系統實現了ISO15765協議,成功通過CAN總線讀取了車輛的OBD-II系統數據,通過上位機監控窗口,能實時檢查汽車故障碼與汽車傳感器數據。可在此基礎上評價汽車健康狀況,并可對故障及早預防,降低行車成本,提供行車安全性;本設計充分考慮中國汽車市場主流總線發展的情況,提供了在復雜的車載環境下遠程車載診斷設備的解決方案。
上傳時間: 2013-11-19
上傳用戶:愛死愛死
2012TI杯陜西賽題H題,2012TI杯陜西賽題-A微弱信號檢測裝置.
上傳時間: 2013-12-17
上傳用戶:362279997
2011全國大賽A題開關電源模塊并聯供電系統
上傳時間: 2013-11-10
上傳用戶:冇尾飛鉈
Avnet Design Service電源實驗室開發出基于MSP430FE427(A) 模塊的電度表解決方案: (1)電壓 (90Vac~264Vac) 與電流 (10Arms) 測量范圍寬 (2)電度表是一種測量用電量的設備 (3)LCD顯示電量 (kWh)、功率 (W)、電壓 (V)、電流 (A)、功率因數(PF) 與溫度 (oC) 測量值 (4)264Vac/63Hz與140mW @90Vac/47Hz條件下,無負載功耗低于300mW (5)測量精度高達2%
上傳時間: 2013-10-13
上傳用戶:cjf0304