stub Shrinking Printed Circuit Boards With Piezoelectric Power Converters - Securities.io
Connect with us

Energy

Shrinking Printed Circuit Boards With Piezoelectric Power Converters

mm

Published

 on

Securities.io is not an investment adviser, and this does not constitute investment advice, financial advice, or trading advice. Securities.io does not recommend that any security should be bought, sold, or held by you. Conduct your own due diligence and consult a financial adviser before making any investment decisions.

Power Converters

“Small is Big,” a widely popular phrase, has proved its merit time and again. Technological interventions that have made our daily life better are becoming smaller, saving space, and increasing efficiency. 

In one of the latest instances of one such intervention, scientists at the University of California San Diego and CEA-Leti developed a cutting-edge, highly sophisticated piezoelectric-based DC-DC converter that could unify all power switches into a single chip. 

Let us start by looking into the merit of this innovation and why it is being lauded with much enthusiasm in the scientific world. 

A High Power Density Converter

Compressing the converter into a single chip primarily achieves an increased power density and births new power dynamics by mixing the benefits of piezoelectric converters with those of capacitive-based DC-DC converters. This technology replaces the earlier bulky inductors and is poised to soon power smartphones, computers, server farms, AR/VR headsets, and more.

Further advantages and novel qualities of this solution were listed in the paper titled, “An Integrated Dual-Side Series/Parallel Piezoelectric Resonator-based 20-to-2.2V DC-DC Converter Achieving a 310% Loss Reduction.” Some of these benefits were as follows:

  • It is the first integrated circuit used for PR-based power conversion. 
  • The solution could achieve up to 310% loss reduction. 
  • The converter could deliver enhanced performance at low voltage conversion ratios, maintaining high efficiency while utilizing piezoelectric materials optimally. 
  • It is capable of offering sophisticated power stages in a small area in comparison with discrete designs while enabling efficient device operation at voltage conversion ratios of less than 0.1.
  • Since the integrated circuit makes it possible to consolidate all power switches onto a single chip, the PCB footprint is reduced significantly. It is also possible to achieve enhanced phase-control precision.

These benefits collectively snowball into something bigger: they not only reduce the demand for piezoelectric material but also empower the scientific community to produce high-power computing servers, automotive systems, USB chargers, and battery-powered devices with the low VCR range DC-DC converter. 

Efficient Piezo-Photomotion and Static Force Measurement Devices

Technical innovations like the one we mentioned above stem from a consistent string of research on the subject. For instance, the December 2023 issue of Sensors and Actuators featured a study that analyzed the performance of on-chip coupled piezo/photodiodes, suggesting a numerical approach for calculating the mechanical efficiency of piezo-photo motion devices

These devices, integrating piezoelectric actuators with silicon solar cells, can convert optical energy to mechanical energy, making them conducive for remote-controlled micro and nanorobots. 

The findings indicated that the mechanical efficiency of the devices did not depend on the input voltage and could improve with thinning and backside etching.

Further, a 2021 study explored the role of piezoelectric sensors in measuring static forces, highlighting their popularity in force measurement applications due to their low cost, linear response, and high sensitivity. These sensors efficiently convert dynamic forces into electrical signals.

Click here to learn how advances in piezoelectric composites are making it possible to harness & interpret kinetic energy.

Studies on Shrinking Printed Circuit Boards

As far as the aspect of shrinking printed circuit boards is concerned, much research has happened in that space as well. A notable study from 2020, published by the IEEE, delved into how electronic components have been shrinking as a result of electronic printed circuit boards becoming denser. 

This research acknowledged the fact that smaller discrete passive devices like surface mount capacitors and resistors were increasing in use, pinpointing a trend towards sizes that would eventually require magnification. 

It also addressed the concerns of defects in these products, advocating for the adoption of appropriate printed circuit board design parameters in determining board pad geometries. 

The findings underscored that smaller pad geometries play a critical role in mitigating tombstoning—a condition where a capacitor or resistor only solders on one end due to the vertical rotation of the component, leading to an open circuit. The researchers also recommended removing the solder mask between the pads to achieve defect-free results. 

Beyond institutional and academic research, numerous businesses are significantly investing in these technologies, devising efficient solutions. The following segments will explore some of these companies and the innovative products they're developing.

#1. ON Semiconductor

ON Semiconductor Corporation successfully acquired Fairchild Semiconductor for US$2.4 billion in cash in September 2016. At the time of acquisition, Fairchild was highly active in the field of piezoelectric power converters. For instance, its FAN8831 single-chip piezoelectric actuator was a product that consisted of a step-up DC-DC converter with an integrated 36V boost switch and a full-bridge output stage. 

The device could drive a Piezo bi-directionally at 120V peak-to-peak from a single 3 V lithium cell. It could operate in a critical conduction mode (CRM), optimized to stay functional in a coupled inductor configuration offering output voltages above 60 V. The solution came with overvoltage- and overcurrent protection and in-built capacities to have thermal shutdowns as and when required. 

An internal circuitry enables the full-bridge gate driver as and when the step-up DC-DC converter output voltage reaches a level commensurate with hysteresis. External resistors helped set the boost voltage, while the step-up current limit could be programmed via the external resistor at the OCP pin. The output H-bridge featured four integrated 75 V P and N channels for the sine wave drive of the Piezo actuator. 

finviz dynamic chart for  ON

For the year ended on December 31, 2023, ON Semiconductor registered a revenue of US$8.253 billion, a minor decline from its previous year's revenue of US$8.326 billion. For the latest year, the net income attributable to ON Semiconductor stood at US$2.183 billion, a slight increase from the previous fiscal's US$1.902 billion. 

#2. Texas Instruments 

Another industry-grade piezo driver with an integrated boost converter came from the Texas Instruments house. The product DRV2700 was a single-chip piezo driver with an integrated 105-V boost switch, integrated power diode, and fully differential amplifier. The device, owing to its inherent versatility, could drive both high-voltage and low-voltage piezoelectric loads. The input signal could be differential or single-ended, AC or DC coupled. The device supported four GPIO-controlled gains, including 28.8dB, 34.8dB, 38.4dB, and 40.7 dB. 

Similar to ON Semiconductor's solution, two external resistors boost the voltage here as well. There are two independent batteries. One has the support of the switch pin, while the other has that of the VDD pin. 

Owing to the product's unique boost converter architecture, it is possible to optimize the DRV2700 circuit's performance for a given inductor. Since the converter draws heavily from a hysteretic architecture, it is possible to minimize switching losses and increase efficiency. 

The device has a typical startup time of 1.5 ms, making it adequately capable of coming out of sleep quickly. It has thermal overload protection features that protect it from damage when overdriven. 

finviz dynamic chart for  TXN

Texas Instruments Incorporated and its subsidiaries posted a revenue of US$17.519 billion for the year ended on December 31, 2023, which was a considerable decline from the previous year's revenue of US$20.028 billion. For FY 2023, diluted earnings per common share stood at US$7.07, while for FY 2022, they were US$9.41. 

#3. Boreas Technologies

Boreas Technologies' product with the tag name ‘BOS1901' is another efficient single-chip piezo actuator driver that is powered by the company's patented capDrive technology, resulting in enhanced standards of energy recovery. The product can drive actuators with waveforms going as high as 190 Vpk-pk while operating from a supply voltage between 3 and 5.5 V. 

Owing to its small size, the product finds application in a range of end-use areas where the minimization of power consumption and heat dissipation is a necessity. 

The high-speed SPI the product uses in its Digital Front End empowers it to share a single communication bus among multi-actuator systems. The Digital Front End also makes it possible to adjust all the settings with only seven passive discrete components. 

BOS1901 is compatible with a range of commercial off-the-shelf inductors. It is also effective for systems that are not equipped to handle reverse current flow. The BOS1901 comes with a unidirectional power input. When activated, this power input makes the driver behave as a resistive load without reducing power efficiency. BOS1901 has a startup time of less than 300 microseconds. Its latency is insignificant.  

According to the latest available information, Boreas Technologies closed a US$12 million financing round in November 2023. The company had decided to utilize the funds to accelerate the high-volume production of its ultra-low-power piezo haptic semiconductors in mobile, PC, and automotive applications.

Small Converters and their Benefits

Engineers across the world are tackling the challenge of creating system designs that are either smaller or pack more functionalities within the existing dimensions. To accommodate more on printed circuit boards, achieving higher PCB density has become crucial. This, however, introduces more complexities for designers, particularly in carrying out board routing and board layout tasks. 

The push to overcome these hurdles has led to the development of analog signal-chain products that help engineers optimize board space without sacrificing the features, cost, simplicity, or robustness. One such notable invention is Op amps, which ensures high performance and a supremely stable amplification circuit with just a few passive components. 

Texas Instrument's Op amps, for example, are available in 16 different packages, which include the industry's smallest single- and quad-channel packages. Similarly, there are small comparators designed with two inputs, one output, and two power-supply pins, named for their to compare input voltages and adjust the output accordingly. The smallest comparator in the industry fits into a WCSP package measuring 0.7X0.7 mm, which is 4% smaller than competing devices and operates down to 1.7 V, making it ideal for space-critical designs like smartphones and other portable or battery-powered applications. 

Small-sized current-sense amps have also come into the picture with the growing demand for system intelligence and power efficiency. Critical systems require better monitoring. This measuring and monitoring of current is possible by sensing the voltage drop across a shunt or current-sense resistor. 

With small-outline transistors measuring as small as 1.6 mm X 1.6 mm, it has been possible to come up with current-sense amplifiers that are 40% smaller than their closest competitive leaded packages. These solutions have been designed for use in space-constrained applications. 

Altogether, research and development have made it possible to considerably reduce the PCB footprint while increasing channel density and leveraging higher integration of other components and features with a small data converter. Such developments will result in more space saved and more efficient designs. 

With electronic gadgets becoming smaller and smaller each passing day and the demand for new features higher, these developments will only gather more and more momentum.  

Gaurav started trading cryptocurrencies in 2017 and has fallen in love with the crypto space ever since. His interest in everything crypto turned him into a writer specializing in cryptocurrencies and blockchain. Soon he found himself working with crypto companies and media outlets. He is also a big-time Batman fan.