National Instruments 781204-01 Waveform Generator

The National Instruments 781204-01 (or, PXIe-5451) is a dual channel, 16 bit arbitrary waveform generator (AWG) capable of 400 MS/s. This PXI Express module offers high resolution signal generation for a wide range of test and measurement applications. The device provides precise waveform outputs across two analog channels with its 16 bit digital to analog converters (DACs). Each channel supports both single ended and differential output configurations that give users flexibility in their test setups. This generator features two distinct output paths: the Main path and the Direct path. The Main path includes a 7 pole elliptic filter for image suppression while the Direct path utilizes a 4 pole filter offering users the ability to select the optimal path depending on their application's frequency response requirements.

The 781204-01's output amplitude ranges from 0.00176 VPP to 10 VPP depending on the load and path used and it features amplitude and offset resolution with precision down to four digits. The 781204-01 waveform generator includes advanced timing and synchronization features along with channel to channel timing alignment accuracy as low as 25 ps for the Direct path. This accuracy is crucial for applications requiring precise phase coherence between channels. The module also provides a software selectable output enable functionality along with a built in 50 Ω termination when disabled. The model supports waveform summing that enables the combination of outputs from multiple signal generators for more complex signal generation.

This waveform generator delivers a Spurious Free Dynamic Range (SFDR) of up to 98 dB without harmonics. The module offers a range of output characteristics that includes DC output resistance of 50 Ω per connector and return loss specifications up to 145 MHz. The device includes load impedance compensation that is performed in software to maintain accurate output amplitude across various load conditions. The 781204-01 module’s physical dimensions are 21.6 cm × 4.0 cm × 13.0 cm and it fits into a 3U two slot PXI Express chassis. It weighs 550 grams and operates within an ambient temperature range of 0 °C to 55 °C with a relative humidity range of 10 % to 90 % non condensing. It also includes self calibration capabilities. The module consumes up to 41.4 W of power drawing from +3.3 VDC and +12 VDC sources.