The current products are optimized to acquire, store and analyze signals in the ±200 mV up to ±2.5V range. The option is supplied as an module/ daughter board within the 22xx range. The company notes that matching the digitizer’s range to the signal under test is important as it ensures maximum dynamic range as well as better measurement accuracy and resolution. If a signal only covers half of a digitizer’s selected full scale range then only half of the digitizer’s available analog-to-digital converter (ADC) resolution can used. With this option, for lower amplitude signals, the ADC's complete dynamic range is available. An 8-bit unit with sensitivity to use the ADC’s full range can deliver better effective resolution than a 10-bit unit using only part of its range.
For extremely low amplitude signals, the 22xx series digitizers can also be used with Spectrum's high bandwidth (up to 2 GHz) external SPA series amplifiers. These free-standing units offer additional x10 (20 dB) or x100 (40 dB) gain making it possible to capture and analyze signals that go down into the low mV ranges. The 22xx series digitizers come in a variety of form factors including PCIe, PXIe and LXI. Models are available with sampling rates of 1.25, 2.5 and 5 Gsample/sec and bandwidths of 500 MHz or 1.5 GHz (700 MHz with low input range option). Full software support is available, including interfacing to packages such as LabVIEW, LabWindows and MATLAB.