Control systems are becoming increasingly dependent on digital processing and so require sensors able to provide direct digital inputs. Sensors based on time measurement, having outputs based on a frequency or phase, have an advantage over conventional analogue sensors in that their outputs can be measured directly in digital systems by pulse counting.
上傳時間： 2013-10-08
上傳用戶：wuyuying
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
cv181l-a-20
標簽： Specification_V 181 1.0 L-A
上傳時間： 2013-11-14
上傳用戶：daijun20803
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
鎖定放大是微弱信號檢測的重要手段。基于相關檢測理論，利用開關電容的開關實現鎖定放大器中乘法器的功能，提出開關電容和積分器相結合以實現相關檢測的方法，并設計出一種鎖定放大器。該鎖定放大器將微弱信號轉化為與之相關的方波，通過后續電路得到正比于被測信號的直流電平，為后續采集處理提供方便。測量數據表明鎖定放大器前級可將10-6 A的電流轉換為10-1 V的電壓，后級通過帶通濾波器級聯可將信號放大1×105倍。該方法在降低噪聲的同時，可對微弱信號進行放大，線性度較高、穩定性較好。 Abstract: Lock-in Amplifying（LIA）is one of important means for weak signal detection. Based on cross-correlation detection theory， switch in the swithched capacitor was used as multiplier of LIA， and a new method of correlation detection was proposed combining swithched capacitor with integrator. A kind of LIA was designed which can convert the weak signal to square-wave， then DC proportional to measured signal was obtained through follow-up conditioning circuit， providing convenience for signal acquisition and processing. The measured data shows that the electric current（10-6 A） can be changed into voltage（10-1 V） by LIA， and the signal is magnified 1×105 times by cascade band-pass filter. The noise is suppressed and the weak signal is amplified. It has the advantages of good linearity and stability.
上傳時間： 2013-11-29
上傳用戶：黑漆漆
PMC和PMC-A系列是小型，高性能，恒定電壓，恒定電流的串聯調節器方式的DC電源。采用串聯調節器方式的設計，可以在低噪聲輸出等級的情況下實現了高穩定的輸出。LED數字儀表在朦朧的環境中也能清晰易讀，電子開關排除了繼電器的顫動，也是這一系列的特征。此外，一部分的PMC-A系列裝備了各種遠程控制功能，通過GPIB，可連接電源控制器。
上傳時間： 2013-10-23
上傳用戶：GHF
用 MSP430實現斜率 A／D轉換的溫度控制系統
上傳時間： 2013-12-21
上傳用戶：athjac
