B&K Precision Rejuvenates Arbitrary/Function Waveform Generator Line

B&K Precision announced that it rejuvenated the 4075B Series of arbitrary/function waveform generators with higher frequency ranges, increased arb memory, and a color LCD. The new 4075B Series offers six new models that directly replace the previous 4075 line with single- and dual-channel 30-MHz (4075B/4078B) and 50-MHz models (4076B/4079B) along with two additional single- and dual-channel 80-MHz models (4077B/4080B). Each model can generate arbitrary waveforms with 14-bit amplitude resolution, a 200-Msps sample rate, and up to 16,000,000 points (depending on model). These instruments are ideal for use in electronic design, sensor simulation, and functional test.4075B_front

Designed with a dual technology architecture, the 4075B Series combines the benefits of traditional DDS (direct digital synthesis) technology and a true AWG (arbitrary waveform generator). DDS allows standard sine, square, and triangle waveforms to be generated with great frequency resolution at a low cost while the true AWG architecture implements custom arbitrary waveforms with a point-by-point design. This design significantly minimizes jitter and improves signal integrity of the arbitrary waveform.

Similar to their predecessors, the new 4075B Series generators offer a menu-driven front panel keypad with rotary encoder knob and convenient range selection buttons to make adjustments quickly and easily. Additionally, all models provide multi-unit/channel synchronization and external triggering capabilities. For precise triggering at specific points in an arbitrary waveform, users can benefit from the instrument’s fully programmable markers, which allow the unit to generate a positive TTL level signal at a specified waveform address.

The 4075B Series provides eight full memory banks per channel for user-defined arbitrary waveforms and 49 locations to store/recall instrument settings. Arbitrary waveforms can be created from the front panel or loaded using B&K’s free WaveXpress waveform editing software. WaveXpress is a comprehensive stand-alone application that offers several waveform editing tools for users to easily create and load complex arbitrary waveforms onto the AWG via the SCPI-compatible USBTMC or GPIB (50 and 80 MHz models only) interface on the rear.

Other features of the 4075B Series include AM/FM/FSK modulation schemes, linear and logarithmic sweep, and built-in overvoltage and short circuit protection for resistive and capacitive loads on all inputs and outputs to prevent accidental damage to the instrument.

Available immediately, B&K Precision’s 4075B Series products are all backed by a standard 3-year warranty and listed at the following prices ranging from $1,495 (Model 4075B) to $3,690 (Model 4080B).

Source: B&K Precision

 

New Dual-Channel Function/Arbitrary Waveform Generators

B&K Precision recently launched its new 4060 Series line of dual channel function/arbitrary waveform generators. The series includes three models that generate sine waveforms up to 80 MHz (4063), 120 MHz (4064), and 160 MHz (4065).BKprecision4060_series

Featuring an advanced pulse generator and high-performance 512k-point arbitrary waveform generator on one channel, these instruments are ideal for use in applications requiring high signal fidelity with extensive modulation and arbitrary waveform capabilities at a value price point.

Unique to the 4060 Series are its advanced pulse generation capabilities. The instruments can generate pulses with low jitter less than 100 ps and output 12-ns width pulses at frequencies as low as 0.1 Hz–a feature not typically found in DDS generators. Rise and fall times are also adjustable within a large range (e.g. users can output pulses with 6 ns rise times combined with 6 s fall times).

All models provide two independent output channels with a large 4.3” color LCD, rotary control knob, numeric keypad, and intuitive function keys to make waveform adjustments quick and easy. Other standard features include a built-in counter, Sync output, trigger I/O terminal, and external 10-MHz reference clock input and output for synchronization of the instrument to another generator.

The 4060 Series offers linear and logarithmic sweep function and a wide variety of modulation schemes for modulated signal applications: amplitude and frequency modulation (AM/FM), double sideband amplitude modulation (DSB-AM), amplitude and frequency shift keying (ASK/FSK), phase modulation (PM), and pulse width modulation (PWM).

Equipped with a high performance 14-bit, 500 Msps, 512k-point arbitrary waveform generator, the 4060 Series provides users 36 built-in arbitrary waveforms and the ability to create and load up to 32 custom arbitrary waveforms using the included waveform editing software via standard USB interface on the rear. A front panel USB host port is available for users to conveniently save waveforms and setups on a USB flash drive or to connect the optional USB-to-GPIB adapter for GPIB connectivity.

Available immediately, B&K Precision’s 4060 Series products are backed by a standard three-year warranty at the following list prices:

4063 — 80 MHz — $1,350
4064 — 120 MHz — $1,670
4065 — 160 MHz — $1,990

For additional technical specifications, accessories, photos, and support documents, visit B&K Precision’s website.

[Source: B&K Precision Corp.]

Arbitrary Waveform Generator

The AWG18 is an arbitrary waveform generator designed for use with Applicos’s ATX-series of test systems. The waveform generator features an 18-bit resolution at a 300 megasamples-per-second (MSPS) data rate and oversampling at a 600-MSPS or 1.2 gigasamples-per-second (GSPS) rate.

Testing analog systems with high-speed 14- and 16-bit data converters requires extremely clean signals. The traditional approach of filtering away the harmonics is insufficient when dealing with a high signal-to-noise ratio (SNR), maintaining a high spurious-free dynamic range (SFDR), or when a low “close-in carrier noise” is preferred. In these cases, the extra precision from an 18-bit signal value can create a reliable test-stand operation and reduce random failures.

ApplicosMany applications need to use signals other than sine waves to make additional time domain measurements. To accommodate this, the AWG18 has two signal paths: one path starts at DC for time domain and general-purpose measurements that require high-level accuracy. The other path runs from 10 to 100 MHz and is optimized for dynamic signal generation in this frequency range. The typical total harmonic distortion (THD) for frequencies up to 50 MHz is above 100 dBc.

Contact Applicos for pricing.

Applicos BV
www.applicos.com

Evaluating Oscilloscopes (Part 4)

In this final installment of my four-part mini-series about selecting an oscilloscope, I’ll look at triggering, waveform generators, and clock synchronization, and I’ll wrap up with a series summary.

My previous posts have included Part 1, which discusses probes and physical characteristics of stand-alone vs. PC-based oscilloscopes; Part 2, which examines core specifications such as bandwidth, sample rate, and ADC resolution; and Part 3, which focuses on software. My posts are more a “collection of notes” based on my own research rather than a completely thorough guide. But I hope they are useful and cover some points you might not have otherwise considered before choosing an oscilloscope.

This is a screenshot from Colin O'Flynn's YouTube video "Using PicoScope AWG for Testing Serial Data Limits."

This is a screenshot from Colin O’Flynn’s YouTube video “Using PicoScope AWG for Testing Serial Data Limits.”

Topic 1: Triggering Methods
Triggering your oscilloscope properly can make a huge difference in being able to capture useful waveforms. The most basic triggering method is just a “rising” or “falling” edge, which almost everyone is (or should be) familiar with.

Whether you need a more advanced trigger method will depend greatly on your usage scenario and a bit on other details of your oscilloscope. If you have a very long buffer length or ability to rapid-fire record a number of waveforms, you might be able to live with a simple trigger since you can easily throw away data that isn’t what you are looking for. If your oscilloscope has a more limited buffer length, you’ll need to trigger on the exact moment of interest.

Before I detail some of the other methods, I want to mention that you can sometimes use external instruments for triggering. For example, you might have a logic analyzer with an extremely advanced triggering mechanism.  If that logic analyzer has a “trigger out,” you can trigger the oscilloscope from your logic analyzer.

On to the trigger methods! There are a number of them related to finding “odd” pulses: for example, finding glitches shorter or wider than some length or finding a pulse that is lower than the regular height (called a “runt pulse”). By knowing your scope triggers and having a bit of creativity, you can perform some more advanced troubleshooting. For example, when troubleshooting an embedded microcontroller, you can have it toggle an I/O pin when a task runs. Using a trigger to detect a “pulse dropout,” you can trigger your oscilloscope when the system crashes—thus trying to see if the problem is a power supply glitch, for example.

If you are dealing with digital systems, be on the lookout for triggers that can function on serial protocols. For example, the Rigol Technologies stand-alone units have this ability, although you’ll also need an add-on to decode the protocols! In fact, most of the serious stand-alone oscilloscopes seem to have this ability (e.g., those from Agilent, Tektronix, and Teledyne LeCroy); you may just need to pay extra to enable it.

Topic 2: External Trigger Input
Most oscilloscopes also have an “external trigger input.”  This external input doesn’t display on the screen but can be used for triggering. Specifically, this means your trigger channel doesn’t count against your “ADC channels.” So if you need the full sample rate on one channel but want to trigger on another, you can use the “ext in” as the trigger.
Oscilloscopes that include this feature on the front panel make it slightly easier to use; otherwise, you’re reaching around behind the instrument to find the trigger input.

Topic 3: Arbitrary Waveform Generator
This isn’t strictly an oscilloscope-related function, but since enough oscilloscopes include some sort of function generator it’s worth mentioning. This may be a standard “signal generator,” which can generate waveforms such as sine, square, triangle, etc. A more advanced feature, called an arbitrary waveform generator (AWG), enables you to generate any waveform you want.

I previously had a (now very old) TiePie engineering HS801 that included an AWG function. The control software made it easy to generate sine, square, triangle, and a few other waveforms. But the only method of generating an arbitrary waveform was to load a file you created in another application, which meant I almost never used the “arbitrary” portion of the AWG. The lesson here is that if you are going to invest in an AWG, make sure the software is reasonable to use.

The AWG may have a few different specifications; look for the maximum analog bandwidth along with the sample rate. Be careful of outlandish claims: a 200 MS/s digital to analog converter (DAC) could hypothetically have a 100-MHz analog bandwidth, but the signal would be almost useless. You could only generate some sort of sine wave at that frequency, which would probably be full of harmonics. Even if you generated a lower-frequency sine wave (e.g., 10 MHz), it would likely contain a fair amount of harmonics since the DAC’s output filter has a roll-off at such a high frequency.

Better systems will have a low-pass analog filter to reduce harmonics, with the DAC’s sample rate being several times higher than the output filter roll-off. The Pico Technology PicoScope 6403D oscilloscope I’m using can generate a 20-MHz signal but has a 200 MS/s sample rate on the DAC. Similarly, the TiePie engineering HS5-530 has a 30-MHz signal bandwidth, and similarly uses a 240 MS/s sample rate. A sample rate of around five to 10 times the analog bandwidth seems about standard.

Having the AWG integrated into the oscilloscope opens up a few useful features. When implementing a serial protocol decoder, you may want to know what happens if the baud rate is slightly off from the expected rate. You can quickly perform this test by recording a serial data packet on the oscilloscope, copying it to the AWG, and adjusting the AWG sample rate to slightly raise or lower the baud rate. I illustrate this in the following video.


Topic 4: Clock Synchronization

One final issue of interest: In certain applications, you may need to synchronize the sample rate to an external device. Oscilloscopes will often have two features for doing this. One will output a clock from the oscilloscope, the other will allow you to feed an external clock into the oscilloscope.

The obvious application is synchronizing a capture between multiple oscilloscopes. You can, however, use this for any application where you wish to use a synchronous capture methodology. For example, if you wish to use the oscilloscope as part of a software-defined radio (SDR), you may want to ensure the sampling happens synchronous to a recovered clock.

The input frequency of this clock is typically 10 MHz, although some devices enable you to select between several allowed frequencies. If the source of this clock is anything besides another instrument, you may have to do some clock conditioning to convert it into one of the valid clock source ranges.

Summary and Closing Comments
That’s it! Over the past four weeks I’ve tried to raise a number of issues to consider when selecting an oscilloscope. As previously mentioned, the examples were often PicoScope-heavy simply because it is the oscilloscope I own. But all the topics have been relevant to any other oscilloscope you may have.

You can check out my YouTube playlist dealing with oscilloscope selection and review.  Some topics might suggest further questions to ask.

I’ve probably overlooked a few issues, but I can’t cover every possible oscilloscope and option. When selecting a device, my final piece of advice is to download the user manual and study it carefully, especially for features you find most important. Although the datasheet may gloss over some details, the user manual will typically address the limitations you’ll run into, such as FFT length or the memory depths you can configure.

Author’s note: Every reasonable effort has been made to ensure example specifications are accurate. There may, however, be errors or omissions in this article. Please confirm all referenced specifications with the device vendor.