ADS131M04-Q1
ZHCSOL7A –MARCH 2022 –REVISED AUGUST 2022
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9 Application and Implementation
备注
以下应用部分中的信息不属于TI 器件规格的范围，TI 不担保其准确性和完整性。TI 的客 户应负责确定
器件是否适用于其应用。客户应验证并测试其设计，以确保系统功能。
9.1 Application Information
9.1.1 Unused Inputs and Outputs
Leave any unused analog inputs floating or connect them to AGND.
Do not float unused digital inputs because excessive power-supply leakage current can result. Tie all unused
digital inputs to the appropriate levels, DVDD or DGND. Leave the DRDY pin unconnected or connect this pin to
DVDD using a weak pullup resistor if unused.
9.1.2 Antialiasing
An analog low-pass filter is required in front of each of the channel inputs to prevent out-of-band noise and
interferers from coupling into the band of interest. Because the ADS131M04-Q1 is a delta-sigma ADC, the
integrated digital filter provides substantial attenuation for frequencies outside of the band of interest up to the
frequencies adjacent to fMOD. Therefore, a single-order RC filter provides sufficient antialiasing protection in the
vast majority of applications.
Choosing the values of the resistor and capacitor depends on the desired cutoff frequency, limiting source
impedance for the ADC inputs, and providing enough instantaneous charge to the ADC input sampling circuit
through the filter capacitor. 图 9-1 shows the recommended filter component values. These recommendations
are sufficient for CLKIN frequencies between 2 MHz and 8.2 MHz.
50 Ω
To ADC
Inputs
4.7 nF
50 Ω
图9-1. Recommended Antialiasing Circuitry
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