Digital oscilloscopes designed by and for testers are bound to face closer scrutiny than most other oscilloscopes. But in the case of the R&S RTO series of digital oscilloscopes from Rohde & Schwarz, these are outstanding instruments whether judged by performance, ease of use, or simply appearance. The firm has previously offered two- and four-channel models available with capture bandwidths of 1 or 2 GHz and sampling rates to 10 GSamples/s. To serve the needs of those not requiring such wide bandwidths, the company recently added a 600-MHz-bandwidth model to the line.
The R&S RTO series of digital oscilloscopes (see figure) benefits from high-power signal processing, using a single-core analog-to-digital converter (ADC) sampling at 10 Gb/s and capable of greater than 7 effective number of bits (ENOB > 7 b), coupled with low-noise front-end electronics to achieve a wide dynamic range. The broadband gain stage supports capture of signals at 1 mV/div. The ADC helps eliminate the ranging typical of conventional oscilloscopes, minimizing overshoot to about 1%. The single-core ADC is based on silicon-germanium (SiGe) semiconductor technology and was designed by Rohde & Schwarz.
In addition, the oscilloscopes feature a custom application-specific integrated circuit (ASIC) that provides dedicated digital signal processing (DSP) for the scopes and enables update rates at 1 million waveforms/s. The ASIC can simultaneously control histograms and masks without losing its full processing speed. It can also coordinate digital spectrum analysis within each scope, and supports a unique digital trigger feature within these oscilloscopes. The latter uses a common signal path for the trigger and the data that it acquires. By sharing the signal path, the time and amplitude offsets that are common to separate trigger and signal-acquisition paths are eliminated.
In addition, the digital trigger will not miss random or transient events that are typically lost by instruments with analog triggers as those triggers are rearming. With the digital trigger, measurement "blind time" is minimized. In fact, with the integrated trigger and decode functionality within the R&S RTO series of digital oscilloscopes, operators can trigger on protocol-specific features for a device under test (DUT), and can display captured waveforms in binary, ASCII, or HEX formats. The trigger and decode feature support SPI, I2C, CAN, LIN, and RS-232 data buses.
Captured signals on the R&S RTO digital oscilloscopes are shown in a vibrant 10.4-in. touchscreen display. Icons can easily be moved about the screen to ease measurement setups. Colors can be coded for different functions and to denote different types of signals. The R&S RTO instruments provide enough processing power to display three waveforms per channel in parallel. Better still, the "QuickMeas" function shows all the measurement values for an active signal at the push of a button.
In addition to their roles as digital storage oscilloscopes (DSOs), the R&S RTO instruments can also operate as mixed-signal oscilloscopes (MSOs) with 16 logic channels. A handy logic-analyzer active probe even contains controls for the scope/analyzer, so that an instrument can operated from the point of the probing, rather than having to set back from a circuit under test. The probe tip also contains a 3.5-digit voltmeter for added measurement power and flexibility. With the logic analyzer probe, the trigger extends to all logic channels when using the probe. Each DSO/MSO contains a logic analyzer module with dedicated field-programmable gate array (FPGA) and its own processing resources, capable of providing logic analysis at oversampling rates to 5 GSamples/s.
The oscilloscopes run with Windows XP. In addition to dedicated input ports for each channel, they offer a pair of Universal Serial Bus (USB) ports for ease of data transfer.
Rohde & Schwarz
8661A Robert Fulton Dr.
Columbia, MD 21046
(410) 910-7800
FAX: (410) 910-7801