参数资料
型号: MAX187CCWE
厂商: MAXIM INTEGRATED PRODUCTS INC
元件分类: ADC
英文描述: +5V, Low-Power, 12-Bit Serial ADCs
中文描述: 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDSO16
封装: 0.300 INCH, SOP-16
文件页数: 17/20页
文件大小: 177K
代理商: MAX187CCWE
M
+5V, Low-Power, 12-Bit S erial ADCs
______________________________________________________________________________________
17
SUPPLIES
+5V
GND
DGND
+5V
DIGITAL
CIRCUITRY
DGND
AGND
VDD
MAX187
MAX189
*OPTIONAL
R* = 10
4.7
μ
F
0.01
μ
F
The ADC results are transmitted across a 1500V isola-
tion barrier provided by three 6N136 opto-isolators.
Isolated power must be supplied to the converter and
the isolated side of the opto-couplers. 74HC595 three-
state shift registers are used to construct a 12-bit paral-
lel data output. The timing sequence is identical to the
timing shown in Figure 8. Conversion speed is limited
by the delay through the opto-isolators. With a 140kHz
clock, conversion time is 100μs.
The universal 12-bit parallel data output can also be
used without the isolation stage when a parallel inter-
face is required. Clock frequencies up to 2.9MHz are
possible without violating the 20ns shift-register setup
time. Delay or invert the clock signal to the shift regis-
ters beyond 2.9MHz.
Layout, Grounding, Bypassing
For best performance, use printed circuit boards. Wire-
wrap boards are not recommended. Board layout
should ensure that digital and analog signal lines are
separated from each other. Do not run analog and digi-
tal (especially clock) lines parallel to one another, or
digital lines underneath the ADC package.
Figure 17 shows the recommended system ground
connections. A single-point analog ground (“star”
ground point) should be established at GND, separate
from the logic ground. All other analog grounds should
be connected to this ground. The 16-pin versions also
have a dedicated DGND pin available. Connect DGND
to this star ground point for further noise reduction. No
other digital system ground should be connected to
this single-point analog ground. The ground return to
the power supply for this ground should be low imped-
ance and as short as possible for noise-free operation.
High-frequency noise in the V
power supply may
affect the ADC’s high-speed comparator. Bypass this
supply to the single-point analog ground with 0.01μF
and 4.7μF bypass capacitors. Minimize capacitor lead
lengths for best supply-noise rejection. If the +5V
power supply is very noisy, a 10
resistor can be con-
nected as a lowpass filter to attenuate supply noise
(Figure 17).
Figure 17. Power-Supply Grounding Condition
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MAX187CCWE+ 功能描述:模数转换器 - ADC 12-Bit 75ksps 5.25V 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
MAX187CCWE+T 功能描述:模数转换器 - ADC 12-Bit 75ksps 5.25V 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
MAX187CCWE-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
MAX187CEPA 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
MAX187CEPA+ 功能描述:模数转换器 - ADC 12-Bit 75ksps 5.25V 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