PicoScope 9404-16 CDR, 4-Channel Sampler-Extended Real-Time Oscilloscope (SXRTO) with Clock Recovery
The PicoScope 9404-16 CDR is the second of its kind: a sampler-extended real-time oscilloscope (SXRTO). It's as easy to use as a real-time scope but gives you a choice of real-time or equivalent-time sampling.
- 16GHz bandwidth, 22ps transition time
- 5TS/s (0.2ps) equivalent-time sampling
- factory-fit 8Gb/s clock and data recovery
- Four 12-bit 500MS/s ADCs
- Pulse, eye and mask testing to 45ps and 11Gb/s
- Logical, configurable and touch-compatible Windows user interface
Comprehensive built-in measurements, zooms, data masks and histograms
Typical applications:
- Telecom and radar test, service and manufacturing
- Optical fiber, transceiver and laser testing (optical to electrical conversion not included)
- RF, microwave and gigabit digital system measurements
- Signal, eye, pulse and impulse characterization
- Precision timing and phase analysis
- Digital system design and characterization
- Eye diagram, mask and limits test to 3Gb/s
- Clock and data recovery at up to 11Gb/s
- Ethernet, HDMI 1, PCI, SATA, USB 2.0
- Semiconductor characterization
- Signal, data and pulse/impulse integrity and pre-compliance testing
Clock and data recovery:
Clock and data recovery (CDR) is a factory-fit trigger feature on this model.
Associated with high-speed serial data applications, clock and data recovery will already be familiar to PicoScope 9300 users. While low-speed serial data can often be accompanied by its clock as a separate signal, at high speed this approach would accumulate timing skew and jitter between the clock and the data that could prevent accurate data decode. Thus high-speed data receivers will generate a new clock, and using a phase locked loop technique they will lock and align that new clock to the incoming data stream. This is the recovered clock and it can be used to decode and thus recover data accurately. Pico Technology have also saved the cost of an entire clock signal path by now needing only the serial data signal.
In many applications requiring our oscilloscopes to view the data, the data generator and its clock will be close at hand and we can trigger off that clock. However, if only the data is available (at the far end of an optical fiber for instance), we will need the CDR option to recover the clock and then trigger off that instead. We may also need to use the CDR option in demanding eye and jitter measurements. This is because we want our instrument to measure as exactly as possible the signal quality that a recovered clock and data receiver will see.
With the PicoScope 9404-16 CDR, the CDR feature can be selected as the trigger source from any input channel. Additionally, for use by other instruments or by downstream system elements, two SMA(f) outputs present recovered clock and recovered data on the rear panel.
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SXRTO explained:
The real-time oscilloscope
Real-time oscilloscopes (RTOs) are designed with a high enough sampling rate to capture a transient, non-repetitive signal with the instrument's specified analog bandwidth. According to Nyquist's sampling theorem, for accurate capture and display of the signal the scope's sampling rate must be at least twice the signal bandwidth. Typical high-bandwidth RTOs exceed this sampling rate by perhaps a factor of two, achieving up to four samples per cycle, or three samples in a minimum-width impulse.
Equivalent-time sampling
For signals close to or above the RTO's Nyquist limit, many RTOs can switch to a mode called equivalent-time sampling (ETS). In this mode the scope collects as many samples as it can after a trigger event, and then continues to collect samples on subsequent trigger events. Because the scope’s sampling clock is independent of the trigger event, each trigger has a random time offset relative to the scope's clock. The scope measures this offset and displays the samples at their correct times. After a large number of trigger events the scope has enough samples to display the waveform with the desired time resolution, called the effective sampling resolution (the inverse of the effective sampling rate), which is many times higher than is possible in real-time (non-ETS) mode. As this technique relies on a random relationship between trigger events and the sampling clock, it is more correctly called random equivalent-time sampling (or sometimes random interleaved sampling, RIS). It can only be used for repetitive signals – those that vary little from one trigger event to the next.
Uniquely, the PicoScope 9404 SXRTO has a maximum effective sampling rate in ETS of 1 TS/s. This corresponds to a timing resolution of only 1 ps, 20,000x higher than its actual maximum sampling rate.
The sampler-extended real-time oscilloscope (SXRTO)
Now that we have a technique (ETS) for extending the sampling rate of a real-time oscilloscope, we find that we can achieve an effective sampling rate far higher than is needed to match the instrument’s analog bandwidth. In order to make better use of these high effective sampling rates, we can increase the analog bandwidth of the scope. Pico has developed a way to achieve this at a moderate cost, compared to the very high cost of increasing the real-time sampling rate. The result is the sampler-extended real-time oscilloscope (SXRTO).
The PicoScope 9404-05 SXRTO has an analog bandwidth of 5 GHz. This means that it requires a sampling rate of at least 10 GS/s, but for an accurate reconstruction of wave shape without interpolation, we need far higher than this. The 9404 gives us 200 sample points in a single cycle at 5 GHz and 140 points in a minimum-width impulse.
So is the SXRTO a sampling scope?
All this talk of sampling rates and sampling modes may suggest that the SXRTO is a type of sampling scope, but this is not the case. The name sampling scope, by convention, refers to a different kind of instrument. A sampling scope uses a programmable delay generator to take samples at regular intervals after each trigger event. The technique is called sequential equivalent-time sampling and is the principle behind the PicoScope 9300 Series sampling scopes. These scopes can achieve very high effective sampling rates but have two main drawbacks: they cannot capture data before the trigger event, and they require a separate clock signal – either from an external source or from a built-in clock-recovery module.
We've compiled a table to show the differences between the types of scopes mentioned on this page.
The example products are all compact, 4-channel, USB PicoScopes:.
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Real-time scope:
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SXRTO:
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Sampling scope:
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Model:
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PicoScope
6407
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PicoScope
9404-05
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PicoScope
9404-15
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PicoScope
9341-50
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Analog bandwidth:
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1GHz*
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5GHz
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16GHz
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25GHz
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Real-time sampling?:
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5GS/s
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500MS/s
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1MS/s
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Sequential equivalent-time sampling?:
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No
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No
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15TS/s
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Random equivalent-time sampling?:
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100GS/s
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1TS/s
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2.5TS/s
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250MS/s
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Trigger on input channel?:
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Yes
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Yes
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Yes, but only to 100MHz bandwidth - requires external trigger or internal clock recovery option
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Pretrigger capture?:
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Yes
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Yes
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No**
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Vertical resolution:
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8 bits
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12 bits
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16 bits
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* Higher-bandwidth real-time oscilloscopes are available from other manufacturers. For example, a 16 GHz analog bandwidth, 80 GS/s, 8 bit sampling model is available for a $119,500 starting price.
Software:
This USB controlled instrument is supplied with PicoSample 4 software. The touch compatible GUI supports set up of the instrument and presents waveforms, measurements and statistics on the user preferred size and format of display. This includes full support for Hi Resolution monitors and projection, for example 4k. Up to four independent zoomed trace views can be used to examine the waveform details.
A wide range of automated and user-configurable signal integrity measurements, mathematics, statistical views and limits test facilities are included for validation and trending of pulse and timing performance, jitter, RZ & NRZ eye diagrams. Industry-standard communications mask tests such as PCIe, GB Ethernet and Serial ATA are included as standard.
While most users will use the PicoSample 4 software in their workplace, for OEM and custom applications the PicoScope 9404 can operate under ActiveX remote control. Programming examples are provided in Visual Basic (VB.NET), MATLAB and LabVIEW, but any programming language or standard that supports the Windows COM interface standard, including JavaScript and C, can be used.
PicoConnect™ 900 Series gigabit and microwave passive test probes are recommended for use with the 9404, offering a range of bandwidths, coupling types and division ratios for diverse applications. The PicoScope 9404 has an active SMA interface to support future configurations and accessories on this new product architecture.
