参数资料
型号: MAX1237MEUA
厂商: MAXIM INTEGRATED PRODUCTS INC
元件分类: ADC
英文描述: 2.7V to 3.6V and 4.5V to 5.5V, Low-Power, 4-/12-Channel, 2-Wire Serial, 12-Bit ADCs
中文描述: 4-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDSO8
封装: MICRO MAX PACKAGE-8
文件页数: 19/22页
文件大小: 407K
代理商: MAX1237MEUA
High-frequency noise in the power supply (V
DD
) could
influence the proper operation of the ADC
s fast com-
parator. Bypass V
DD
to the star ground with a network of
two parallel capacitors, 0.1μF and 4.7μF, located as
close as possible to the MAX1236
MAX1239 power-sup-
ply pin. Minimize capacitor lead length for best supply
noise rejection, and add an attenuation resistor (5
) in
series with the power supply if it is extremely noisy.
Definitions
Integral Nonlinearity
Integral nonlinearity (INL) is the deviation of the values on
an actual transfer function from a straight line. This straight
line can be either a best straight-line fit or a line drawn
between the endpoints of the transfer function, once offset
and gain errors have been nullified. The MAX1236
MAX1239
s INL is measured using the endpoint.
Differential Nonlinearity
Differential nonlinearity (DNL) is the difference between
an actual step width and the ideal value of 1 LSB. A
DNL error specification of less than 1 LSB guarantees
no missing codes and a monotonic transfer function.
Aperture Jitter
Aperture jitter (t
AJ
) is the sample-to-sample variation in
the time between the samples.
Aperture Delay
Aperture delay (t
AD
) is the time between the falling
edge of the sampling clock and the instant when an
actual sample is taken.
Signal-to-Noise Ratio
For a waveform perfectly reconstructed from digital sam-
ples, the theoretical maximum SNR is the ratio of the full-
scale analog input (RMS value) to the RMS quantization
error (residual error). The ideal, theoretical minimum ana-
log-to-digital noise is caused by quantization error only
and results directly from the ADC
s resolution (N Bits):
SNR
MAX[dB]
= 6.02
dB
N + 1.76
dB
In reality, there are other noise sources besides quanti-
zation noise: thermal noise, reference noise, clock jitter,
etc. SNR is computed by taking the ratio of the RMS
signal to the RMS noise, which includes all spectral
components minus the fundamental, the first five har-
monics, and the DC offset.
Signal-to-Noise Plus Distortion
Signal-to-noise plus distortion (SINAD) is the ratio of the
fundamental input frequency
s RMS amplitude to the
RMS equivalent of all other ADC output signals.
SINAD dB
SignalRMS
NoiseRMS THDRMS
(
)
log
=
×
20
M
2.7V to 3.6V and 4.5V to 5.5V, Low-Power,
4-/12-Channel, 2-Wire Serial, 12-Bit ADCs
______________________________________________________________________________________
19
011...111
011...110
OUTPUT CODE
ZS = AIN-
000...010
000...001
000...000
111...111
111...110
111...101
100...001
100...000
-FS+1/2 LSB
AIN-
INPUT VOLTAGE (LSB)
+FS - 1 LSB
REF
1 LSB = V
V
REF
AIN-
REF
+ AIN-
FS = V
REF
+ AIN-
-FS = -V
Figure 13. Bipolar Transfer Function
GND
V
LOGIC
= 3V/5V
3V OR 5V
SUPPLIES
DGND
3V/5V
GND
*OPTIONAL
4.7
μ
F
R* = 5
0.1
μ
F
V
DD
DIGITAL
CIRCUITRY
MAX1236–
MAX1239
Figure 14. Power-Supply Grounding Connection
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MAX1237MEUA+ 功能描述:模数转换器 - ADC 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
MAX1237MEUA+T 功能描述:模数转换器 - ADC 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
MAX1237MEUA-T 功能描述:模数转换器 - ADC 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
MAX1238EEE 功能描述:模数转换器 - ADC 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
MAX1238EEE/V+ 功能描述:模数转换器 - ADC 12-Bit 12Ch 94.4ksps 5.5V Precision ADC 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