Tektronix Technologies' Next Generation Oscilloscope

In the frequent contact with engineers, engineers are now facing new challenges. More and more scenes need to accurately test high-speed small signals. Traditional 8-bit oscilloscopes are embarrassing. Engineers have concerns about existing oscilloscope test results. The best way to improve test accuracy is to increase the oscilloscope ADC bits.

For many mobile electronics designs, low power consumption is a trend that is driving down the standby voltage or current. More power supplies require smaller ripples in DC output to improve power efficiency or have various types of low-power sensor applications in automotive electronics, autonomous robots or medical electronics, involving many small electrical signal conversions, which are all small-scale Examples of higher signal measurement accuracy requirements.

With all of these test scenarios in mind, the heart of the new 4 Series MSOs is a 12-bit analog-to-digital converter (ADC) that provides 16 times the vertical resolution of a traditional 8-bit ADC. Unlike some oscilloscope vendors, their 12-bit vertical resolution is calculated by DSP rather than the true 12-bit analog-to-digital conversion achieved by a hardware ADC. Tektronix' true 12-bit ADC is built on the Tektronix Tek049 ASIC.

Not only do the 4 Series MSO users have a true 12-bit ADC, but they can also apply a new high-resolution mode, a unique hardware-based finite impulse response (FIR) filter that further improves vertical resolution based on the selected sampling rate. rate. The FIR filter maintains the maximum bandwidth of this sample rate while preventing aliasing and noise cancellation from the oscilloscope amplifier and ADC, which is higher than the available bandwidth of the selected sample rate. The high resolution mode always provides at least 12 vertical resolutions and scales to 16-bit vertical resolution at ≤125 MS/s sample rate.

How to solve the problem of small signal test accuracy?
Tektronix is ​​faced with a new generation of oscilloscopes in the 4 Series, 5 Series, and 6 Series. Its hardware uses a 12-bit ADC to achieve unparalleled resolution, helping engineers capture small signals. Thanks to the Tek049 chip, the new ASIC is the core of Tektronix' future oscilloscopes, supporting high-definition touch-screen displays, up to eight FlexChannel inputs, and 12-bit vertical resolution, powering the next-generation oscilloscopes that modern engineers need.

Tek049 is Tektronix's newly developed ASIC (Application Specific Integrated Circuit), a highly integrated chip system (SOC) mixed-signal ASIC with 400 million transistors and 2 billion connections, forming four internal ADCs (modules) Digital converter) and integrated DSP (digital signal processor). Fabricated in a 40 nm RF CMOS process, the Tek049 is packaged in a 1927-pin fine-gap ball grid array to create a unique chip from Tektronix' new generation of oscilloscopes.

Figure 1 Tek049 chip

The new 12-bit ADC is the fastest converter in the world, with an internal operating speed of 25 GS/s and a sampling rate of 25% higher per channel than previous oscilloscopes. The 12-bit implements 4096 vertical analog-to-digital conversion levels with a resolution 16 times higher than an oscilloscope with an 8-bit ADC. Each ADC channel is based on an Interleaved Continuous Proximity Register (SAR) architecture, and each Tek049 chip includes four ADCs, achieving a total throughput of 100 GS/s.

12bit oscilloscope becomes the "core" trend
Power design engineers face more scenarios for small signal testing. With the development and application of power electronics technology, many power supply ripples have become very small, especially the board-level design power rail ripple test from tens of mV to more than ten mV or even several mV, the traditional 8-bit oscilloscope can not Meet the test needs.

For example, in the debugging of the switching device system, the engineer will pay more attention to the oscillation signal of the switch edge. This requires the oscilloscope to ensure that the vertical direction satisfies a large range of processes, and at the same time has sufficient resolution to capture the details of the narrow amplitude oscillation signal.

Figure 2 Using a 8- and 12-bit oscilloscope to test the switch-on signal

Figure 2 shows a comparison of the instantaneous oscillating waveforms of the same switch circuit switch with different vertical resolution oscilloscopes. To test a complete waveform, you need to select a larger range for the oscilloscope settings; at the same time, the engineer needs to oscillate the edge to see the details. Figures 3 and 4 show the actual test results of the two oscilloscopes under the same conditions (250 MSa/s sampling rate, 10k samples, 2V per cell). It can be seen that the MDO4000C oscilloscope (8-bit) test results, because of its vertical resolution limitation, there is a significant quantization step after amplification, which is basically impossible to analyze; and the waveform captured by Tektronix' new 4-series MSO oscilloscope (12-bit) can still be amplified. Accurately reproduce the details of the oscillating signal.

Figure 3. MDO4000C oscilloscope (8bit) test results

Figure 4. New 4 Series MSO Oscilloscope (12bit) Test Results

The oscilloscope's 12-bit ADC has become a trend in the test industry. Tektronix' new generation of 12-bit oscilloscopes greatly increases the test confidence of engineers and provides engineers with an accurate way to test high-speed signals.