- 您現在的位置：買賣IC網 > PDF目錄373915 > AD7720 (Analog Devices, Inc.) CMOS Sigma-Delta Modulator PDF資料下載
參數資料
| 型號： | AD7720 |
| 廠商： | Analog Devices, Inc. |
| 英文描述： | CMOS Sigma-Delta Modulator |
| 中文描述： | 的CMOSΣ-Δ調制器 |
| 文件頁數： | 7/16頁 |
| 文件大小： | 232K |
| 代理商： | AD7720 |
AD7720
–7–
REV. 0
T E RMINOLOGY (IDE AL FIR FILT E R USE D WIT H AD7720
[FIGURE 1])
Integral Nonlinearity
T his is the maximum deviation of any code from a straight line
passing through the endpoints of the transfer function. T he
endpoints of the transfer function are zero scale (not to be con-
fused with bipolar zero), a point 0.5 LSB below the first code
transition (100 . . . 00 to 100 . . . 01 in bipolar mode and
000 . . . 00 to 000 . . . 01 in unipolar mode) and full scale, a
point 0.5 LSB above the last code transition (011 . . . 10 to
011 . . . 11 in bipolar mode and 111 . . . 10 to 111 . . . 11 in
unipolar mode). T he error is expressed in LSBs.
Differential Nonlinearity
T his is the difference between the measured and the ideal 1 LSB
change between two adjacent codes in the ADC.
Common-Mode Rejection Ratio
T he ability of a device to reject the effect of a voltage applied to
both input terminals simultaneously—often through variation of
a ground level—is specified as a common-mode rejection ratio.
CMRR is the ratio of gain for the differential signal to the gain
for the common-mode signal.
Unipolar Offset E rror
Unipolar offset error is the deviation of the first code transition
from the ideal VIN(+) voltage which is (VIN(–) + 0.5 LSB)
when operating in the unipolar mode.
Bipolar Offset E rror
T his is the deviation of the midscale transition (111 . . . 11
to 000 . . . 00) from the ideal VIN(+) voltage which is (VIN(–)
–0.5 LSB) when operating in the bipolar mode.
Gain E rror
T he first code transition should occur at an analog value 1/2
LSB above minus full scale. T he last code transition should
occur for an analog value 3/2 LSB below the nominal full scale.
Gain error is the deviation of the actual difference between first
and last code transitions and the ideal difference between first
and last code transitions.
Signal-to-(Noise + Distortion)
Signal-to-(Noise + Distortion) is measured signal-to-noise at the
output of the ADC. T he signal is the rms magnitude of the
fundamental. Noise plus distortion is the rms sum of all of the
nonfundamental signals and harmonics to half the output word
rate (f
MCLK
/128), excluding dc. Signal-to-(Noise + Distortion) is
dependent on the number of quantization levels used in the
digitization process; the more levels, the smaller the quantiza-
tion noise. T he theoretical Signal-to-(Noise + Distortion) ratio
for a sine wave input is given by
Signal-to-
(
Noise + Distortion) =
(6.02
N +
1.76)
dB
where
N
is the number of bits.
T otal Harmonic Distortion
T otal Harmonic Distortion (T HD) is the ratio of the rms sum
of harmonics to the rms value of the fundamental. For the
AD7720, T HD is defined as
THD
=
20 log
(
V
2
2
+
V
3
2
+
V
4
V
1
2
+
V
5
2
+
V
6
2
)
where
V
1
is the rms amplitude of the fundamental and
V
2
,
V
3
,
V
4
,
V
5
and
V
6
are the rms amplitudes of the second through the
sixth harmonic.
Spurious Free Dynamic Range
Spurious free dynamic range is the difference, in dB, between
the peak spurious or harmonic component in the ADC output
spectrum (up to f
MCLK
/128 and excluding dc) and the rms value
of the fundamental. Normally, the value of this specification will
be determined by the largest harmonic in the output spectrum
of the FFT . For input signals whose second harmonics occur in
the stop band region of the digital filter, a spur in the noise floor
limits the spurious free dynamic range.
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 distortion 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).
相關PDF資料 |
PDF描述 |
|---|---|
| AD7720BRU | CMOS Sigma-Delta Modulator |
| AD7721 | CMOS 16-Bit, 468.75 kHz, Sigma-Delta ADC |
| AD7721AN | CMOS 16-Bit, 468.75 kHz, Sigma-Delta ADC |
| AD7721AR | CMOS 16-Bit, 468.75 kHz, Sigma-Delta ADC |
| AD7721SQ | CMOS 16-Bit, 468.75 kHz, Sigma-Delta ADC |
相關代理商/技術參數 |
參數描述 |
|---|---|
| AD7720BRU | 功能描述:IC MODULATOR SIGMA-DELTA 28TSSOP RoHS:否 類別:集成電路 (IC) >> 數據采集 - 模數轉換器 系列:- 標準包裝:1,000 系列:- 位數:12 采樣率（每秒）:300k 數據接口:并聯 轉換器數目:1 功率耗散（最大）:75mW 電壓電源:單電源 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:24-SOIC（0.295"，7.50mm 寬） 供應商設備封裝:24-SOIC 包裝:帶卷 (TR) 輸入數目和類型:1 個單端，單極；1 個單端，雙極 |
| AD7720BRU-REEL | 制造商:Analog Devices 功能描述:ADC Single Delta-Sigma 25Msps 16-bit Serial 28-Pin TSSOP T/R |
| AD7720BRU-REEL7 | 制造商:Analog Devices 功能描述:ADC Single Delta-Sigma 25Msps 16-bit Serial 28-Pin TSSOP T/R 制造商:Rochester Electronics LLC 功能描述:- Tape and Reel |
| AD7720BRUZ | 功能描述:IC MODULATOR SIGMA-DELTA 28TSSOP RoHS:是 類別:集成電路 (IC) >> 數據采集 - 模數轉換器 系列:- 標準包裝:1,000 系列:- 位數:12 采樣率（每秒）:300k 數據接口:并聯 轉換器數目:1 功率耗散（最大）:75mW 電壓電源:單電源 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:24-SOIC（0.295"，7.50mm 寬） 供應商設備封裝:24-SOIC 包裝:帶卷 (TR) 輸入數目和類型:1 個單端，單極；1 個單端，雙極 |
| AD7720BRUZ-REEL | 功能描述:IC MODULATOR SIGMA-DELTA 28TSSOP RoHS:是 類別:集成電路 (IC) >> 數據采集 - 模數轉換器 系列:- 標準包裝:1,000 系列:- 位數:12 采樣率（每秒）:300k 數據接口:并聯 轉換器數目:1 功率耗散（最大）:75mW 電壓電源:單電源 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:24-SOIC（0.295"，7.50mm 寬） 供應商設備封裝:24-SOIC 包裝:帶卷 (TR) 輸入數目和類型:1 個單端，單極；1 個單端，雙極 |
發布緊急采購，3分鐘左右您將得到回復。