поискавой системы для электроныых деталей |
|
AD7478AAKS-REEL7 датащи(PDF) 11 Page - Analog Devices |
|
AD7478AAKS-REEL7 датащи(HTML) 11 Page - Analog Devices |
11 / 24 page REV. C AD7476A/AD7477A/AD7478A –11– TERMINOLOGY Integral Nonlinearity This is the maximum deviation from a straight line passing through the endpoints of the ADC transfer function. For the AD7476A/ AD7477A/AD7478A, the endpoints of the transfer function are zero scale, a point 1 LSB below the first code transition, and full scale, a point 1 LSB above the last code transition. Differential Nonlinearity This is the difference between the measured and the ideal 1 LSB change between any two adjacent codes in the ADC. Offset Error This is the deviation of the first code transition (00 . . . 000) to (00 . . . 001) from the ideal, i.e., AGND + 1 LSB. Gain Error This is the deviation of the last code transition (111 . . . 110) to (111 . . . 111) from the ideal, i.e., VREF – 1 LSB after the offset error has been adjusted out. Track-and-Hold Acquisition Time The track-and-hold amplifier returns to track mode at the end of conversion. The track-and-hold acquisition time is the time required for the output of the track-and-hold amplifier to reach its final value, within ±0.5 LSB, after the end of conversion. See the Serial Interface section for more details. Signal-to-(Noise + Distortion) Ratio (SINAD) This is the measured ratio of signal-to-(noise + distortion) at the output of the A/D converter. The signal is the rms amplitude of the fundamental. Noise is the sum of all nonfundamental signals up to half the sampling frequency (fS/2), excluding dc. The ratio is dependent on the number of quantization levels in the digiti- zation process; the more levels, the smaller the quantization noise. The theoretical signal-to-(noise + distortion) ratio for an ideal N-bit converter with a sine wave input is given by Signal-to-(Noise + Distortion) = (6.02 N + 1.76) dB Thus, it is 74 dB for a 12-bit converter, 62 dB for a 10-bit con- verter, and 50 dB for an 8-bit converter. Total Unadjusted Error (TUE) This is a comprehensive specification that includes the gain, linearity, and offset errors. Total Harmonic Distortion (THD) Total harmonic distortion is the ratio of the rms sum of har- monics to the fundamental. It is defined as THD VV VVV V 2 2 3 2 4 2 5 2 6 2 1 dB () = + +++ 20 log where V1 is the rms amplitude of the fundamental, and V2, V3, V4, V5, and V6 are the rms amplitudes of the second through the sixth harmonics. Peak Harmonic or Spurious Noise (SFDR) Peak harmonic or spurious noise is defined as the ratio of the rms value of the next largest component in the ADC output spectrum (up to fS/2 and excluding dc) to the rms value of the fundamental. Normally, the value of this specification is deter- mined by the largest harmonic in the spectrum. But for ADCs where the harmonics are buried in the noise floor, it will be a noise peak. Intermodulation Distortion (IMD) With inputs consisting of sine waves at two frequencies, fa and fb, any active device with nonlinearities will create distortion products at sum and difference frequencies of mfa ± nfb, where m and n= 0, 1, 2, 3, and so on. Intermodulation distortion terms are those for which neither m nor n are equal to zero. For example, the second-order terms include (fa + fb) and (fa – fb), while the third-order terms include (2fa + fb), (2fa – fb), (fa + 2fb), and (fa – 2fb). The AD7476A/AD7477A/AD7478A are tested using the CCIF standard where two input frequencies are used (see fa and fb on the specification pages). In this case, the second-order terms are usually distanced in frequency from the original sine waves, while the third-order terms are usually at a frequency close to the input frequencies. As a result, the second- and third-order terms are specified separately. The calculation of the intermodulation dis- tortion is per the THD specification, where it is the ratio of the rms sum of the individual distortion products to the rms amplitude of the sum of the fundamentals expressed in dBs. |
Аналогичный номер детали - AD7478AAKS-REEL7 |
|
Аналогичное описание - AD7478AAKS-REEL7 |
|
|
ссылки URL |
Конфиденциальность |
ALLDATASHEETRU.COM |
Вашему бизинису помогли Аллдатащит? [ DONATE ] |
Что такое Аллдатащит | реклама | контакт | Конфиденциальность | обмен ссыками | поиск по производителю All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |