NI 5160/5162 Filters

The NI 5160/5162 offers two filters that limit the bandwidth of the signal path: a 20 MHz noise filter and a 175 MHz noise filter. Both filters are available through the 1 MΩ and 50 Ω signal paths. The 20 MHz filter is intended to reduce noise when the signal content is 20 MHz or less, and the 175 MHz filter is intended to reduce noise when the signal content is 175 MHz or less.

The noise filter is useful for rejecting out of band or background noise in lower frequency applications. An example application would be characterization of video waveforms in the presence of IF noise. Because most of the signal content is below the 8 MHz range, the 20 MHz noise filter is ideal. Many standard noise tests specify a 20 MHz noise bandwidth.

Note   To change the filter type, call niScope Configure Chan Characteristics VI or the niScope_ConfigureChanCharacteristics function and set the Max Input Frequency parameter to the appropriate value. For example, setting the Max Input Frequency parameter to 8M would enable the 20 MHz filter.

The following figure shows a characteristic frequency response of the 20 MHz noise filter.

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The following figure shows a characteristic frequency response of the 175 MHz noise filter.

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Refer to the hardware specifications document for more information on these filters.