An increase in the number of portable electronic devices has subsequently led to a requirement for high-power charging. Foo Leng Leong, senior technical marketing manager, STMicroelectronics, in a conversation with EFY, explains about the company’s latest offering for USB-C type data transfer and charging applications.
STMicroelectronics has released a high-power receiver and transmitter that can gain up to 80 per cent efficiency
It, as the company informed, is suitable for portable applications and is completely ROHS compliant
In order to simplify the existing, highly-cluttered data transfer connectivity methods, STMicroelectronics (ST) has been involved in developing high-end products for USB-C type data transfer and charging for several years. In 2017, this was achieved through the launch of STUSB1602 and now with the introduction of STWLC68, a high-power receiver and a transmitter.
“ST has a comprehensive roadmap for wireless charging solutions spanning across the full power range. We want to introduce new features for end-users and at the same time, respect the environment, all thanks to the highest efficiency of our innovative solutions,” said Foo Leng Leong, senior technical marketing manager, ACP, STMicroelectronics.
The aim is to provide users with an efficient wireless charging that has advanced safety features and can enable rapid power transfer.
Curiosity about USB-C
Since its inception in 2015, USB-C has been dominating the market with its high-power output. However, the wireless charging standard has not kept up pace with this advancement.
“A key reason is due to the lack of a wireless receiver that is capable of delivering high power. Most wireless devices follow Qi EPP standards of 15W, which is lower than the technological limits of wireless charging,” stated Leong.
Leong also hopes that the same will change soon. “ST solutions can go beyond this and we’re working with standardizing groups to get these approved for the consumers’ benefit. Our target is to achieve wireless charging to be faster than wired charging,” he explained.
Worst case power loss at around three to four cent only
For RX only, the worst case power loss, as ST informed, is around three to four percent at high temperature conditions. However, the system losses can be higher than this due to coupling and alignment losses and heat losses in the coil and capacitive tank.
He added, “We have developed and implemented (in compliance to Qi 1.2.4 standard) our proprietary protocol which allows for higher power and also authentication, handshaking and pairing.”
Suitable for applications from 5W to 20W
The STWLC68 has a fully integrated low-impedance, high-voltage synchronous rectifier and low drop-out linear regulator, for achieving high efficiency and low power dissipation. For serving a wider range of applications, the STWLC68 is suitable for applications from 5W to 20W.
I2C interface allows firmware and platform parameters to be customized in the device and the configuration can be programmed into the embedded OTP. Besides this, the wireless charging IC family is supported by an online simulation environment.
“To name just a few of the configuration parameters that can be embedded into the STWLC68 OTP, there is protection, in-band communication, proprietary protocols, current limits and GPIO functions,” said Leng Leong.
He added, “We have a design suite that helps our users design and implements wireless charging efficiently and effectively. Our online GUI has such tools, including coil selection and design tools and system tuning and configuration adjustments to assist in the application of our solutions.”
Its operating temperature range is from 0 degrees Celsius to 85 degrees Celsius. But power losses can be around three per cent to four per cent at high temperatures (for Rx only).
