The National Instruments PXI-5621 is a high-speed digitizer with a 14-bit resolution and a sampling rate capability ranging from 1 kS/s to 64 MS/s. Operating within a nominal input impedance of 50 Ω, this single-channel device is optimized for DC coupling, allowing it to accurately capture a wider passband, including DC signals. The PXI-5621 can handle input signal levels up to +8 dBm (±0.794 Vp) and features diverse triggering options, including software, digital, and immediate triggers for flexible acquisition scenarios. It includes an external frequency reference input (SMA female connector) and an external trigger input (PFI 1 - SMB male) to enhance its versatility.

Designed to mitigate distortion from differential nonlinearity in the Analog-Digital Converter, the PXI-5621 incorporates a Dither function, which can be applied to the input signal in the range between 150 Hz and 4 MHz, although its use is not recommended during time-domain data sampling. The digitizer is equipped with a 64 MB memory buffer and supports multi-record capturing mode, making it particularly effective for demanding measurement tasks. The compact form factor of 3.9 x 6.3 x 0.8 inches and a weight of 7.8 ounces ensures easy integration into various PXI systems. While officially classified as obsolete, the PXI-5621 continues to be available for purchase and repair through Apex Waves. Users can access both the user manual and maintenance manual for further guidance and support. For pricing inquiries, please contact a sales representative.