A "symphony" of precision: harmonizing power and signal integrity with low-noise technology

In the summer of 2004, a standard ultrasound revealed that Mr. and Mrs. Steve Schnier were expecting twins. But during another ultrasound a few weeks later, they were surprised to find that this time it showed triplets.

Steve, a systems engineer in Texas Instruments' Switching Regulator Group, suspected that unwanted noise or signal interference in the ultrasonic system was causing this anomaly.

“I never really realized it until I started working in medical imaging devices and wireless infrastructure, where noise is a big issue,” says Steve, now a grown-up triplet. Adult, preparing to take college entrance examination.

距离 Steve 遇到超声波检查异常已经过去将近 20 年。在这些年里，技术取得了显著的进步。不过，探寻降低系统噪声并提高信号质量来实现精密信号链的方法，仍是众多行业的设计工程师面临的挑战。

During the operation of complex power systems, no noise is an ideal state, but it is difficult to achieve. Noise is an electrical product produced by all components and can come from many sources, including electromagnetic interference (EMI) and heat sources. Noise corrupts signals and causes distortion in measurements, which can lead to errors, miscalculations or misinterpretations, ultimately affecting the accuracy and reliability of the system.

Noise can also make electronic systems more susceptible to external factors such as temperature fluctuations and voltage changes. These external factors can further amplify the noise, adding additional errors.

In sensitive systems such as medical imaging equipment, too much noise can cause images to be blurry or potentially inaccurate. Additionally, noise can negatively impact the accuracy and precision of test and measurement equipment, leading to inaccurate results.

Noise challenges are particularly important for automotive engineers designing electric vehicles (EVs) or developing autonomous driving systems where precision signals are critical for safety and performance.

Jeff Morroni, director of power management R&D at Texas Instruments Applied Research Laboratory Kilby Labs, said: “In electric vehicles, sensitive systems used to implement safety or parking functions are susceptible to excessive noise, and these systems are not compatible with Noise-generating high-power components are located in close proximity, which is what our low-noise and high-precision technology attempts to solve.

Sensitive systems need to be robust enough to withstand noise generated by heat sources and physical stresses. The stress generated when a car hits a speed bump is enough to affect signal accuracy. Noise can affect the operation of autonomous driving systems, and light detection and ranging (lidar) systems can suffer from "ghosting," which is the generation of false or misleading signals or images. At the same time, the lithium-ion batteries powering the electric vehicle revolution can become unstable and pose safety risks if they overheat.

Power management devices used in the signal transmission and conditioning chain minimize distortion and reduce noise and are therefore critical to achieving a clear signal. These power devices can also power clock ICs as well as precision ADCs (analog-to-digital converters) and DACs (digital-to-analog converters), enabling a complete low-noise and high-precision signal chain.

降低噪声的一个更具体的好处是可以延长电动汽车的续航里程。开发人员测量电动汽车电池的电压信号越准确，电动汽车单次充电的行驶里程越长。 测量精度达到毫伏（千分之一伏）的高精度电池监控器和平衡器，例如德州仪器的 BQ79718-Q1，可显著延长续航里程。

Jeff said: "We are talking about an extended range of 10% to 15%, which is achievable just by more accurate voltage measurement. This directly reduces the battery cost and meets the customer value proposition."

Maximizing noise reduction requires looking at every link in the signal chain. Semiconductors themselves generate noise that affects the performance of other components. However, this noise can be "cancelled" using passive filtering, control techniques, and other unique process techniques. In addition, power components such as low-noise low-dropout regulators (LDOs), buck converters, and voltage references also contribute to low system noise.

For decades, low-noise LDOs have become the industry standard for providing low-noise power due to their ease of integration and ability to provide ultra-clean, ultra-precision power rails for highly sensitive applications. For example, Texas Instruments' TPS7A94 offers the lowest output noise power supply on the market, the highest output voltage accuracy, and the highest power supply rejection ratio to generate a clean power rail that does not impact system performance.

At the same time, Texas Instruments' TPS62913/2 series of buck converters reduce noise in the power supply structure without the need for a traditional LDO to regulate the voltage. Although it may produce slightly more noise than an LDO, it saves space and cost, improves efficiency, reduces power consumption, and reduces thermal issues.

As a fundamental building block in data conversion systems, voltage references also play an important role in reducing noise. Voltage references require excellent stability to avoid introducing errors into the signal chain. Texas Instruments' REF70 ultra-precision voltage reference sets an excellent low-noise benchmark, unlocking the extra bits of the ADC and enabling accurate measurements.

Katelyn said: “I think the voltage reference is the cornerstone of the signal chain design because every component in it, whether it’s an ADC or a DAC, has to be referenced to a voltage. Since a lot of noise can cause system measurements to go out of specification, reducing the noise Very important. If this happens, you have to take the entire system offline for debugging and calibration. If we can extend the calibration cycle, we can provide higher throughput and less downtime to the customer, which really provides value to the customer. ”

Although noise is an inevitable product of power supply architectures, using Texas Instruments' low-noise and high-precision technology allows engineers to design systems with smaller size and superior accuracy at lower cost.

Steve 表示：“噪声对很多应用中的敏感系统有显著影响，作为三胞胎的父亲和一名工程师，我亲眼见证了这一点。在过去的 18 年里，德州仪器一直致力于发展降噪技术，但仍面临诸多挑战。我们的持续创新可帮助工程师克服这些挑战，进而大幅提升系统性能。”