In frequent contact with engineers, it is found that engineers are now facing new challenges. More and more scenarios need to accurately test high-speed small signals. Traditional 8-bit oscilloscopes are embarrassing, and engineers have concerns about the test results of existing oscilloscopes. The most ideal way to improve the test accuracy is to increase the oscilloscope ADC bits.
For many mobile electronic product designs, low power consumption is a growing trend, driving down the standby voltage or current. More power supplies require less ripple on the DC output to improve power efficiency or there are various types of low-power sensor applications in automotive electronics, autonomous robots or medical electronics, which involve many small electrical signal conversions, which are low-amplitude An example where the signal measurement accuracy is required to be high.
Taking all of these test scenarios into account, at the heart of the new 4 Series MSO 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 suppliers, their 12-bit vertical resolution is obtained through DSP calculations rather than a true 12-bit analog-to-digital conversion through hardware ADCs. The Tektronix true 12-bit ADC is built on the Tektronix Tek049 ASIC.
Users of the 4 Series MSO not only have a true 12-bit ADC, but can also apply a new high-resolution mode, a unique hardware-based Finite Impulse Response (FIR) filter, which further improves vertical resolution based on the selected sampling rate. Rate. The FIR filter maintains the maximum bandwidth for that sample rate, while preventing aliasing and removing noise from the oscilloscope amplifier and ADC, above the available bandwidth for the selected sample rate. High-resolution mode always provides at least 12-bit vertical resolution and extends to 16-bit vertical resolution at ≤ 125 MS/s sample rates.
How to solve the small signal test accuracy problem?

Tektronix is facing the new generation of oscilloscopes 4 series, 5 series and 6 series. Its hardware adopts 12-bit ADC to achieve unparalleled resolution, helping engineers to capture tiny signals. That's thanks to the Tek049 chip, the new ASIC at the heart of Tektronix' future oscilloscopes, supporting high-definition touchscreen displays, up to 8 FlexChannel inputs, 12-bit vertical resolution, and more, powering the next-generation oscilloscopes that modern engineers need to design.
Tek049 is an ASIC (Application-Specific Integrated Circuit) newly developed by Tektronix, which is a highly integrated System-on-Chip (SOC) mixed-signal ASIC containing 400 million transistors and 2 billion connections, forming 4 internal ADCs (analog digital converter) and integrated DSP (Digital Signal Processor). Manufactured on a 40 nm RF CMOS process, the Tek049 is housed in a 1927-pin fine-gap ball grid array package, creating a chip unique to Tektronix' next-generation oscilloscopes.

Figure 1 Tek049 chip

The new 12-bit ADC is currently the fastest converter in the world, operating at an internal rate of 25 GS/s and has a per-channel sample rate 25% higher than previous comparable oscilloscopes. The 12 bits realize 4096 vertical analog-to-digital conversion levels, and the resolution is 16 times higher than that of an oscilloscope using an 8-bit ADC. Each ADC channel is based on an interleaved sequential proximity register (SAR) structure, and each Tek049 chip includes four ADCs, achieving a total throughput of 100 GS/s.

The 12bit oscilloscope has become a "core" trend power supply design engineer, facing more scenarios of small signal testing. With the development and application of power electronics technology, many power supply ripples have become very small, especially for board-level design power rail ripple testing from tens of mV to the current tens of mV or even several mV, traditional 8bit oscilloscopes can no longer be meet testing needs.
For example, in the system debugging of switching devices, engineers will pay more attention to the oscillating signal at the switching edge. This requires the oscilloscope to have sufficient resolution to capture the details of the narrow-range oscillating signal while ensuring that the vertical direction meets a large range.

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

Figure 2 shows the comparison of the instantaneous oscillation waveforms of the same switching circuit when the switch is turned on by using oscilloscopes with different vertical resolutions. In order to test the complete waveform, it is necessary to select a larger range for the oscilloscope setting; at the same time, the engineer needs to amplify the oscillation of the edge to observe the details. Figure 3 and Figure 4 are the actual test results of these two oscilloscopes under the same setting conditions (250MSa/s sampling rate, 10k samples, 2V per grid). It can be seen from the test results of MDO4000C oscilloscope (8-bit) that due to the limitation of its vertical resolution, there are obvious quantization steps after zooming in, which is basically impossible to analyze; while the waveform captured by Tektronix' new 4 series MSO oscilloscope (12-bit) can still be zoomed in. Accurately reproduce the details of oscillatory signals.
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 testing industry. Tektronix's new generation of 12-bit oscilloscope has greatly increased the testing confidence of engineers, and also provided engineers with a method to accurately test high-speed signals.