Oscilloscopes are considered to be the most used class of test instrument. However, oscilloscopes have limitations too, particularly in voltage range and in their ability to give users the information they want.

You've probably worked around your oscilloscope's limited input voltage ranges by adding signal-conditioning buffers and attenuators. To get the information you need from a measurement, you've likely written applications that processes the raw data and produce test results. With the PXIe-5164 PXIe oscilloscope, you can have both in a single-slot module.

The module's Xilinx Kintex-7 410T FPGA lets you perform signal processing right on the board, relieving the host system of computationally intensive tasks. You can program the oscilloscope using LabVIEW FPGA to add applications such as software radio or FFT.

The PXIe-5164 is a two-channel oscilloscope with 14-bit resolution, 1Gsample/s sampling rate, 400MHz analog bandwidth and 1.5Gsamples of acquisition memory. National Instruments specifies its input voltage range as "up to 100Vpp with 250Vpp offset." What does that mean? Let's look at it graphically.

NI PXIe-5164 OffsetDiagram (cr) Figure 1: PXIe-5164 has an input range of up to 100Vpp with 250Vpp offset. (Source: National Instruments)

At 0V offset, the input voltage range is ±50V (100Vpp). The graphic shows that you can add offset to that voltage range to fit your application. Offsets of -150V and 200V are shown. The sine wave indicates the voltage ranges for these three offset values. At the extremes, the input voltage range is -150V to -250V up to 150V to 250V.

Like most oscilloscopes, the PXIe-5164 has both 50Ω and 1MΩ input impedances. The figure below shows its input stage where the module bypasses the 1MΩ input section when operating at 50Ω. This ability to switch input paths reduces noise, according to National Instruments. The input amplifier's gain is adjusted through the amplifier's feedback loop rather than with attenuators.

NI PXIe-5164 InputDiagram (cr) Figure 2: Input stage where module bypasses the 1MΩ input section when operating at 50Ω. (Source: National Instruments)