参数资料
型号: 5962-9475502MPX
厂商: ANALOG DEVICES INC
元件分类: ADC
英文描述: 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, CDIP8
封装: GLASS SEALED, CERDIP-8
文件页数: 3/14页
文件大小: 349K
代理商: 5962-9475502MPX
AD7893
–11–
REV. E
Effective Number of Bits
The formula for signal to (noise + distortion) ratio (see Termi-
nology section) is related to the resolution or number of bits in
the converter. Rewriting the formula gives a measure of perfor-
mance expressed in effective number of bits (N):
N = (SNR – 1.76) / 6.02
where SNR is Signal to (Noise + Distortion) Ratio.
The effective number of bits for a device can be calculated from
its measured signal to (noise + distortion) ratio. Figure 13 shows
a typical plot of effective number of bits versus frequency for the
AD7893-2 from dc to fSAMPLING/2. The sampling frequency is
102.4 kHz. The plot shows that the AD7893 converts an input
sine wave of 51.2 kHz to an effective numbers of bits of 11,
which equates to a signal to (noise + distortion) level of 68 dB.
INPUT FREQUENCY – kHz
12.0
11.5
10.0
0
51.2
25.6
EFFECTIVE
NUMBER
OF
BITS
11.0
10.5
Figure 13. Effective Number of Bits vs. Frequency
The same data is presented in Figure 11 as in Figure 10 except
that, in this case, the output data read for the device occurs dur-
ing conversion. This has the effect of injecting noise onto the die
while bit decisions are being made; this increases the noise gen-
erated by the AD7893. The histogram plot for 8192 conversions
of the same dc input now shows a larger spread of codes with
the rms noise for the AD7893-2 increasing to 210
V. This ef-
fect will vary depending on where the serial clock edges appear
with respect to the bit trials of the conversion process. It is pos-
sible to achieve the same level of performance when reading
during conversion as when reading after conversion, depending
on the relationship of the serial dock edges to the bit trial points.
CODE
7500
(X–4)
(X–3)
OCCURRENCES
OF
CODE
7000
6500
6000
0
5500
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
(X–2)
(X–1)
(X+1) (X+2) (X+3) (X+4)
X
SAMPLING
FREQUENCY = 102.4kHz
T
A
= +25
°C
Figure 11. Histogram of 8192 Conversions with Read Dur-
ing Conversion
Dynamic Performance
With a combined conversion and acquisition time of 7.5
s, the
AD7893 is ideal for wide bandwidth signal processing applica-
tions. These applications require information on the ADC’s
effect on the spectral content of the input signal. Signal to (noise
+ distortion) ratio, total harmonic distortion, peak harmonic or
spurious noise, and intermodulation distortion are all specified.
Figure 12 shows a typical FFT plot of a 10 kHz, 0 V to +2.5 V
input after being digitized by the AD7893-2, operating at a
102.4 kHz sampling rate. The signal to (noise + distortion)
ratio is 71.5 dB, and the total harmonic distortion is –83 dB.
FREQUENCY – kHz
SNR IS SIGNAL TO (NOISE AND DISTORTION) RATIO
0
–30
–180
0
51.2
25.6
SIGNAL
AMPLITUDE
dB
–60
–80
–120
SAMPLE RATE = 102.4kHz
INPUT FREQUENCY = 10kHz
SNR = 71.5dB
TA = +25°C
Figure 12. AD7893 FFT Plot
相关PDF资料
PDF描述
5962-9555601Q2A SPECIALTY ANALOG CIRCUIT, CQCC20
5962-9555601QPA SPECIALTY ANALOG CIRCUIT, CDIP8
TLE2425CD SPECIALTY ANALOG CIRCUIT, PDSO8
TLE2425CPSR SPECIALTY ANALOG CIRCUIT, PDSO8
TLE2425MDR SPECIALTY ANALOG CIRCUIT, PDSO8
相关代理商/技术参数
参数描述
5962-9475601MPA 制造商:Rochester Electronics LLC 功能描述:- Bulk
5962-9475701HXA 功能描述:模数转换器 - ADC Analog to Digital Converter RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32
5962-9475701HXC 功能描述:模数转换器 - ADC Analog to Digital Converter RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32
5962-9475901MYC 制造商:Rochester Electronics LLC 功能描述:10BIT 40 MSPS A/D IC IC - Bulk
5962-9476101MXC 功能描述:CPLD - 复杂可编程逻辑器件 ISPLSI 102460LH/883 SMD Version RoHS:否 制造商:Lattice 系列: 存储类型:EEPROM 大电池数量:128 最大工作频率:333 MHz 延迟时间:2.7 ns 可编程输入/输出端数量:64 工作电源电压:3.3 V 最大工作温度:+ 90 C 最小工作温度:0 C 封装 / 箱体:TQFP-100