NI identifies the PXI-5900 as a 2-Channel PXI Differential Amplifier and lists it as a primary hardware module rather than an accessory. The NI model page also states that the module is designed for use with PXI oscilloscopes, particularly the PXI-5922, and indicates a 1-slot PXI form factor. NI lists part number 780166-01 on the model page, while the product certifications page separately describes the hardware as “CCA, NI PXI-5900, DIFFERENTIAL AMPLIFIER” under identifier 196368-01L, which is a certification/assembly identifier rather than a separately confirmed sellable variant. https://www.ni.com/en-id/shop/model/pxi-5900.html https://www.ni.com/en/support/documentation/product-certifications/model.pxi-5900.html
According to NI’s specifications page, the PXI-5900 provides 2 differential channels with BNC input and SMB output connectors. NI specifies AC, DC, and GND input coupling, along with software-selectable input impedance of either 50 Ω ±2% or 1 MΩ ±1.0% in parallel with 60 pF. The published vertical gain is 0.25 ±0.2%, and zero input offset error is specified as 500 μV. https://www.ni.com/docs/en-US/bundle/pxi-5900-specs/page/specs.html
For signal performance, NI specifies 6 MHz small-signal bandwidth at -3 dB for a 1 Vpp input, 1 dB passband flatness from DC to 5 MHz, and typical CMRR of 70 dB at 60 Hz. Additional typical characteristics include input bias current below 10 pA at 25 °C, slew rate of 100 V/μs referred to balanced differential input, rise time below 180 ns for a 0 to 10 V step and below 60 ns for a 0 to 2 V step, and THD and noise below 0.02% at VIN = 2 Vrms and 10 kHz. https://www.ni.com/docs/en-US/bundle/pxi-5900-specs/page/specs.html
