The National Instruments 781949-01, also known as the PXIe-6556, is an advanced PXI Digital Waveform Instrument specifically designed for digital waveform generation and analysis. This versatile module is ideal for DC parametric testing, characterization, and interfacing applications. It offers high-speed digital waveform sampling capabilities of up to 200 MHz across 24 single-ended digital pins, allowing for precise testing configurations with user-programmable voltage levels.

The 781949-01 features per-pin parametric measurement unit (PPMU) functionality, enabling detailed monitoring and control for each channel, which enhances the accuracy of digital signal characterization and analysis. Additionally, the module is equipped with hardware comparison capabilities for bit-error testing, making it well-suited for challenging testing environments. An innovative active load configuration further extends its functionality when connected to an external source-measure unit (SMU), facilitating high-precision DC measurements and expanding its application range in parametric testing scenarios.

Programmability is a standout feature of the device, providing per-channel control over timing, voltage levels, and signal direction. It supports various signal types, including ground-referenced and single-ended signals, and boasts a resolution of up to 122 μV, allowing for precise voltage control tailored to specific testing requirements. The digital generation channels offer configurable drive voltage levels, swing, and impedance to maximize signal integrity with downstream components.

This instrument also includes safety features such as output protection and software-selectable tristate control. For digital acquisition, the 781949-01 includes adjustable acquisition voltages and thresholds to ensure accurate signal processing. With options for 50 Ω or high-impedance termination, the device is equipped to handle diverse input requirements. Moreover, the active load channels provide meticulous control over load characteristics, enabling detailed analysis of the device under test (DUT) under various stress conditions. The 781949-01 is characterized by its extensive range of programmable levels and exceptional accuracy, making it an essential tool for comprehensive digital waveform analysis.

The technical specifications include a model name of PXIe-6556, a maximum sampling rate of 200 MHz, memory size of 8 Mbit per channel for both acquisition and generation, 4 input and 2 output clock terminals, and external force/sense channels with analog bandwidths of 3 MHz and 30 kHz, respectively.