PXIe modules for precision signal generation

October 21, 2016 // By Graham Prophet
Spectrum Instrumentation’s (Grosshansdorf, Germany) M4x series of PXIe Arbitrary Waveform Generators (AWGs) offer a cost effective solution for automated testing applications that require fast and accurate electronic signal generation. Combined speed and flexibility allows continuously replayed signals at a high output rate.

Based on the modular PXIe instrumentation standard, the M4x series includes five new modules that provide one, two or four channels. Each channel is equipped with 16-bit digital-to-analogue converters and the various models (see table 1) have maximum clocking rates of 625 Msample/sec or 1.25 Gsample/sec. The combination of high resolution and fast clocking rates supports generating precise and flexible wave shapes with frequency content from DC to 400 MHz.


The dual width 3U AWGs feature a PXIe x4 Gen 2 interface that allows waveform data to be transferred to the module’s 4 GB of on-board memory at speeds up to 1.4 GB/sec. Fully PXIe compliant, the modules can be used in any PXIe or PXI hybrid chassis. Support is also provided for chassis distribution features such as the PXIe/PXI reference clock, star-trigger and trigger bus.


To allow the generation of long and complex waveforms, the AWGs include a number of operating modes such as Single-Shot, Loop, FIFO, Gating and Sequence Replay. In FIFO mode, the instruments can stream data continuously from PC memory to the AWG memory over the PXIe interface. The AWGs can output signals while new waveform data is being sent to the on-board memory. The operating modes, together with the fast data transfer and the large on-board memories, make the M4x series AWGs among the most flexible on the market. Each channel of the AWG is clocked using a precision phase locked loop (PLL) control system that can be generated internally or from an external clock or reference.


The AWGs have programmable output levels from ±200 mV to ±4V (±5V for 625 Msample/sec models) into high-impedance and ±100 mV up to ±2 V (±2.5V for 625 Msample/sec models) for 50Ω termination. Using 16-bit digital to analog conversion, the AWGs offer signal-to-noise (SNR) up to 72 dB, spurious free dynamic range (SFDR) up to 98 dB and noise spectral density (NSD) at an impressive