ST’s first 1,500 W TVS diode SMB15F in tiny SMB Flat package has been certified
“ST’s new SMB15F series of 1,500 W TVS diodes in an SMB Flat package has been certified. Compared with the SMC package, the volume of the SMB Flat package is reduced by 50%. In addition to the improvement in space, the price is more advantageous, saving the budget for the enterprise. In addition, the smaller size is beneficial for increasing power density and increasing efficiency. In fact, the leakage current of the SMB15F series is approximately five times lower than the competition. Therefore, these 1500 W devices have been evaluated in 5G equipment and other applications.
ST’s new SMB15F series of 1,500 W TVS diodes in an SMB Flat package has been certified. Compared with the SMC package, the volume of the SMB Flat package is reduced by 50%. In addition to the improvement in space, the price is more advantageous, saving the budget for the enterprise. In addition, the smaller size is beneficial for increasing power density and increasing efficiency. In fact, the leakage current of the SMB15F series is approximately five times lower than the competition. Therefore, these 1500 W devices have been evaluated in 5G equipment and other applications.
Why did STMicroelectronics introduce two SMB15F series – SMB15FxxA and SMB15FxxAY?
Part numbers ending in “A” are intended for industrial applications, while those ending in “AY” are automotive grade. The silicon-based components are the same, but the “AY” model undergoes more rigorous testing and usage tracking to pass AEC-Q101 automotive-grade qualification. There are currently 26 models in each series – based on the maximum reverse working voltage of the device. For example, the SMB15F11AY is an automotive-grade version of our 1,500 W model with a maximum reverse operating voltage of 11V. The maximum reverse working voltage of each series is as low as 5 V and as high as 64 V.
Why does the industry need a 1,500 W TVS in an SMB Flat package?
In 2019, STMicroelectronics conducted the first inspection of the SMB15F device, which is very symbolic and has been confirmed in important markets. For example, at the 2019 Industry Summit in China, we confirmed that there is a growing demand for higher power density. Robotic applications have previously used IGBT drivers, and silicon carbide technology is transforming electric vehicles. Fast forward to 2021 and more components requiring high power protection in tiny packages are on Display at our Industry Summit. From drones to smart building solutions to e-bikes, protecting sensitive components from inrush currents is becoming increasingly important. As products are getting smaller and power consumption is getting higher and higher, the use of smaller, flatter packaging is imperative.
Difference in volume between SMC package and SMB Flat package
Will SMB15F replace 1,500 W TVS in SMC package?
The current 1,500 W devices are here to stay. We understand that some companies need time to switch to the new package. Once the team has qualified the device and used it in the design, it is natural to take full advantage of it. However, based on market reality, we strongly call for this cost-effective SMB Flat package. So our goal is to help teams transition from SMC packaging to SMB Flat packaging. For example, many components in the SMC package have an equivalent version in the SMB15F series, which helps engineers continue to use their familiar PCBs as long as the size is compatible.
Why do we have to wait until 2021 for 1,500 W TVS in SMB Flat package to be certified?
ST’s SMB15F is AEC-Q101 automotive-qualified
The technical complexities of transitioning from SMC to SMB Flat packaging are easily overlooked, as we have mastered TVS product assembly line technology for over 30 years to be able to provide this modern cost-effective solution and lead the industry.
SMC package (left) vs SMB Flat package (right)
The SMB15F device represents a new chapter in the history of TVS diodes. ST’s SMC series has been around for more than 20 years, and the SMB Flat models are expected to achieve similar success as they not only reduce cost but also increase reliability. Like the previous generation, the SMB15F is so robust that we can offer industrial-grade and automotive-qualified versions (AEC-Q101) of the same die. ST has also increased production capacity to ensure that companies looking to jump-start the trend can adopt new products with confidence and confidence that they can meet customer demand.
How does the SMB15F device compare to alternatives in the SMC package?
For managers or inexperienced engineers, the benefits of further flattening the package are not significant. Therefore, STMicroelectronics has written application notes to illustrate different benchmarks. For example, the figure below compares similar devices in SMC and SMB Flat packages. The blue curve shows that the voltage during clamping is almost the same, with only 0.3 V between the two due to dissipation. Likewise, inrush current (pink curve) shows a similar behavior. Therefore, this document proves that the SMB15F device can reduce cost and PCB area without sacrificing its protection capability.
Waveform comparison between SMC package (Figure 10) and SMB Flat package (Figure 11) devices
Are there other TVS devices in the tiny flat package?
STMicroelectronics also offers 400 W and 600 W transient voltage suppressors in SMA Flat and SMB Flat packages. The device is pin-compatible with previous-generation devices, and the 600 W model is available in SMA Flat and SMB Flat packages, helping some companies transition from traditional SMB devices to SMA Flat packages. In fact, the SMB Flat package provides an intermediate step. In many cases, while manufacturers already have pick-and-place machines compatible with thinner devices, engineers tend to ignore these components and focus on other aspects of the design. By increasing the accessibility of the 1,500 W TVS diode with a further flattened package, designers can transition to a more cost-effective solution while focusing on other parts of the PCB.