参数资料
| 型号： | AD7874BN |
| 厂商： | Analog Devices Inc |
| 文件页数： | 16/16页 |
| 文件大小： | 0K |
| 描述： | IC DAS 12BIT 4CH 5V 28-DIP |
| 标准包装： | 1 |
| 类型： | 数据采集系统（DAS） |
| 分辨率（位）： | 12 b |
| 采样率（每秒）： | 116k |
| 数据接口： | 并联 |
| 电压电源： | 双 ± |
| 电源电压： | ±5V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 通孔 |
| 封装/外壳： | 28-DIP（0.600"，15.24mm） |
| 供应商设备封装： | 28-PDIP |
| 包装： | 管件 |
AD7874
REV. C
–9–
Total Harmonic Distortion (THD)
Total Harmonic Distortion (THD) is the ratio of the rms sum
of harmonics to the rms value of the fundamental. For the
AD7874, THD is defined as
THD
= 20 log
V
2
2 +V
3
2 +V
4
2 +V
5
2 +V
6
2
V
1
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 harmonic. The THD is also derived from the FFT plot of
the ADC output spectrum.
Intermodulation Distortion
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, n = 0, 1, 2, 3 . . ., etc. Intermodulation terms are those for
which neither m or 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).
Using the CCIF standard where two input frequencies near the
top end of the input bandwidth are used, the second and third
order terms are of different significance. 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 intermodu-
lation distortion is as per the THD specification where it is the
ratio of the rms sum of the individual distortion products to the
rms amplitude of the fundamental expressed in dBs. In this case,
the input consists of two, equal amplitude, low distortion sine
waves. Figure 10 shows a typical IMD plot for the AD7874.
Figure 10. AD7874 IMD Plot
Peak Harmonic or Spurious Noise
Harmonic or Spurious Noise is defined as the ratio of the rms
value of the next largest component in the ADC output spec-
trum (up to fs/2 and excluding dc) to the rms value of the fun-
damental. Normally, the value of this specification will be
determined by the largest harmonic in the spectrum, but for
parts where the harmonics are buried in the noise floor the peak
will be a noise peak.
AC Linearity Plot
When a sine wave of specified frequency is applied to the VIN in-
put of the AD7874 and several million samples are taken, a his-
togram showing the frequency of occurrence of each of the 4096
ADC codes can be generated. From this histogram data it is
possible to generate an ac integral linearity plot as shown in Fig-
ure 11. This shows very good integral linearity performance
from the AD7874 at an input frequency of 10 kHz. The absence
of large spikes in the plot shows good differential linearity. Sim-
plified versions of the formulae used are outlined below.
INL(i )
= (V(i) V(o)) 4096
V ( fs)
V(o)
i
where INL(i) is the integral linearity at code i. V(fs) and V(o) are
the estimated full-scale and offset transitions, and V(i) is the es-
timated transition for the i
th code.
V(i), the estimated code transition point is derived as follows:
V (i )
= ACos
π cum(i)
[]
N
where A is the peak signal amplitude, N is the number of histo-
gram samples
and cum(i )
=
n
=o
i
∑ V(n)occurrences
Figure 11. AD7874 AC INL Plot
相关PDF资料 |
PDF描述 |
|---|---|
| LTC6905CS5#TRPBF | IC OSC SILICON 170MHZ TSOT23-5 |
| D38999/26FG16HN | CONN PLUG 16POS STRAIGHT W/PINS |
| V28A36M200BF3 | CONVERTER MOD DC/DC 36V 200W |
| MS3121E14-18P | CONN RCPT 18POS CBL MNT W/PINS |
| V28A28M200BF | CONVERTER MOD DC/DC 28V 200W |
相关代理商/技术参数 |
参数描述 |
|---|---|
| AD7874BNZ | 功能描述:IC DAS 12BIT 4CH 5V 28-DIP RoHS:是 类别:集成电路 (IC) >> 数据采集 - ADCs/DAC - 专用型 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:50 系列:- 类型:数据采集系统（DAS） 分辨率（位）:16 b 采样率（每秒）:21.94k 数据接口:MICROWIRE?，QSPI?，串行，SPI? 电压电源:模拟和数字 电源电压:1.8 V ~ 3.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:40-WFQFN 裸露焊盘 供应商设备封装:40-TQFN-EP（6x6） 包装:托盘 |
| AD7874BQ | 功能描述:IC DAS 12BIT 4CH 5V 28-CDIP RoHS:否 类别:集成电路 (IC) >> 数据采集 - ADCs/DAC - 专用型 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:50 系列:- 类型:数据采集系统（DAS） 分辨率（位）:16 b 采样率（每秒）:21.94k 数据接口:MICROWIRE?，QSPI?，串行，SPI? 电压电源:模拟和数字 电源电压:1.8 V ~ 3.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:40-WFQFN 裸露焊盘 供应商设备封装:40-TQFN-EP（6x6） 包装:托盘 |
| AD7874BR | 制造商:Analog Devices 功能描述:ADC Single SAR 116ksps 12-bit Parallel 28-Pin SOIC W 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:Analog Devices 功能描述:IC 12-BIT ADC |
| AD7874BRMZ | 制造商:Analog Devices 功能描述: |
| AD7874BRZ | 功能描述:IC DAS 12BIT 4CH LC2MOS 28-SOIC RoHS:是 类别:集成电路 (IC) >> 数据采集 - ADCs/DAC - 专用型 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:50 系列:- 类型:数据采集系统（DAS） 分辨率（位）:16 b 采样率（每秒）:21.94k 数据接口:MICROWIRE?，QSPI?，串行，SPI? 电压电源:模拟和数字 电源电压:1.8 V ~ 3.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:40-WFQFN 裸露焊盘 供应商设备封装:40-TQFN-EP（6x6） 包装:托盘 |
发布紧急采购，3分钟左右您将得到回复。