The digital input module shares a common clock and trigger with the base board, ensuring that both digital and analog inputs are fully synchronized. This makes the combination ideal for a wide variety of mixed-signal test applications. The option is available for all "44" series digitizer models with up to 500 MS/s and two or four analog inputs. Additional analog channels can be acquired by linking up to eight digitizers together with Spectrum's unique Star-Hub clock and trigger distribution system.
The Spectrum M4i.44xx series of PCIe digitizer cards comprises eight different models. Users can select versions with two or four analog channels and sampling rates of 180 or 250 MS/s with 16-bit resolution, or higher rates of 400 or 500 MS/s with 14-bit resolution. The "44" series digitizer cards are fully equipped with extensive analog signal conditioning (6 input ranges, selectable input impedance, compensation, etc.) and advanced triggering capabilities. Acquired data can be stored in a generous 2 GS of onboard memory or transferred to a PC in a variety of efficient memory read modes, including FIFO streaming, at speeds up to 3.4 GB/s.
The cards are also packed with features for easy integration into any test setup. For example, they have additional front-panel connections including two external trigger inputs, an external clock reference input, a clock output, and three general-purpose I/O lines available for asynchronous I/O operations. They come complete with software and all the necessary tools to work in virtually any system, whether integrated into an automated test platform for electronic components or used as the key data acquisition device in scientific, communications, energy, aerospace, or medical applications.
The new M4i.44xx-DigSMA digital input option has a separate PCIe faceplate, occupying an additional PCIe slot, with an SMA x8 connector. Designed for versatility, each input has an impedance of 10 kOhms (at 3.3 V). This allows the inputs to handle 3.3 V LVTTL signals with input voltage levels between -0.5 V and +4.0 V. The digital input bandwidth is 125 MHz, and the software selection allows for both synchronous and asynchronous acquisition modes.
When using the digital input option, digital data is stored within the analog samples by reducing the resolution of one channel. This enables phase synchronization of the analog and digital signals, as the one-bit digital signals are placed within the higher-order bits of the analog waveforms. For example, if eight digital channels are used, the resolution of the analog channels would be reduced from 16 to 14 bits, and two of the digital signals would be added to each analog channel of a four-channel digitizer.
For applications requiring more channels, Spectrum allows multiple M4i.44xx series cards to be connected using its Star-Hub system. Star-Hub enables up to eight cards to share a common clock and trigger. This allows for the creation of larger systems simply by adding more cards. For example, connecting three M4i.4451-x8 digitizers—two with the M4i.44xx-DigSMA digital option and one with the Star-Hub option—creates a single system with 12 analog and 16 digital channels.
All Spectrum digitizers come complete with software drivers that allow for fully customized configurations capable of generating matched mixed-mode test solutions. The digitizers and digital input option are compatible with the full Spectrum Software Development Kit (SDK), which includes programming using C++, C#, VB.NET, Python, Java, LabVIEW, or MATLAB. The SDK is included with every unit, along with a basic version of Spectrum's software, SBench 6. This program allows users to control all hardware modes and settings through a simple, user-friendly interface, providing a straightforward tool for basic digitizer setup and testing.
For more demanding applications that may require data analysis and documentation, Spectrum also offers its SBench 6 Professional software. This powerful software expands upon the capabilities of the base version with additional features such as FFT analysis, analog and digital waveform display modes, an XY display, a function interpreter, additional parameter measurements, export to ASCII, Wave, and MATLAB formats, commenting functions (for annotating signals or displays), and even a reporting and printing function.
