NOVOSENSE: Ultra-wide-body digital isolators make high-voltage applications more efficient and reliable

SHANGHAI, Oct. 24, 2023 /PRNewswire/ — In recent years, the number of photovoltaic systems, chargers, new energy vehicles, energy storage facilities and other emerging technologies is increasing, and the installed base of industrial control devices, power supply, electricity and other conventional applications is still climbing. In this setting, high-voltage digital control applications pose growing isolation requirements, and the market sees a strong demand for high-efficiency and high-reliability digital isolators accordingly.

In high-voltage systems, a reliable isolation gate must be built using isolation means, which electrically isolates sensitive electronic components from fast transient high-voltage components to ensure power safety, better system performance and higher reliability. To this end, many factors need to be taken into account, including isolation rating, creepage distance and electric clearance, common-mode transient immunity (CMTI), and electromagnetic interference (EMI).

Wide bandgap (WBG) devices like SiC and driver products pose higher requirements for isolators while continuously improving the power density. Digital isolator now has become one of the semiconductor devices that help unlock the huge potential of high-voltage applications. It is widely used in photovoltaic systems, new energy vehicles, industrial automation systems, isolated SPI, RS232, RS485, general-purpose multi-channel isolation unit, and motor control. 

Ultra-wide-body package emerging at the right time

In photovoltaic applications, monocrystalline silicon and polycrystalline silicon materials are required. To improve the power density of photovoltaic modules, the bus voltage has been increased to 1500 V. This requires an isolator that provides a longer creepage distance to meet the voltage withstand and creepage distance requirements specified in China’s national standard GB4943.1-2022. As a response, some wide-body (SOP) and even ultra-wide-body (DWW) packages emerged. Actually, different manufacturers designate different names for ultra-wide-body packages.

Ultra-wide-body digital isolator is a highly reliable isolation product that features high electromagnetic immunity, low electromagnetic radiation and low power consumption, and can withstand higher isolation surge voltage. The creepage distance of the ultra-wide-body package is up to 15 mm, which can meet the safety requirements of customers’ high-voltage systems. In photovoltaic systems for example, the creepage distance of isolator under 1500 V enhanced insulation condition shall be more than 14 mm, as required in IEC 62109.

NSI82xx digital isolators from NOVOSENSE are products in ultra-wide-body package. They provide a long creepage distance of 15 mm, and an outstanding EMC property. This makes this digital isolator series a perfect choice for photovoltaic facilities and other high-voltage systems having a high creepage distance requirement. Moreover, the NSI82xx series is compatible with high-precision, high-speed and two-way digital isolators from other manufacturers, such as ISO78xx, ISO774x-Q1, and ACNT-H6xL, etc.

Depending on applications, NSI82xx series are divided into two sub-series – NSI82xx-DSWWR and NSI82xx-Q1SWWR high-reliability, multichannel ultra-wide-body digital isolators. NSI82xx-DSWWR sub-series is designed for industrial applications, including NSI822xWx-DSWWR (2-channel), NSI823xWx-DSWWR (3-channel), and NSI824xWx-DSWWR (quad-channel). NSI82xx-Q1SWWR sub-series is suitable for automotive applications, including NSI822xWx-Q1SWWR (2-channel), NSI823xWx-Q1SWWR (3-channel), and NSI824xWx-Q1SWWR (quad-channel).

According to the available information, NSI82xx-DSWWR ultra-wide-body digital isolators started mass production in January 2022, and a total of more than one million devices have been sold currently. More specifically, customers from power supply, NEVs, electric power, industrial control, photovoltaic, energy storage and charging piles are using ultra-wide-body digital isolators from NOVOSENSE.

Answering high efficiency, high reliability and multi-function requirements

For example, the quad-channel NSI824x digital isolator has UL1577 safety approval, and can withstand several levels of insulation voltage (3 kVrms, 3.75 kVrms, 5 kVrms and 8 kVrms). It’s noted that the ultra-wide-body package provides insulation voltage withstand capability of up to 8 kVrms, data rate of up to 150 Mbps, and CMTI of up to 200 kV/μs (min.).

The NSI824x device provides digital channel direction configuration and the default output level configuration when the input power is lost. Thanks to a wide supply voltage range, NSI824x can be directly connected with most digital interfaces, and allows easy level shift. Moreover, high system level EMC performance enhances its reliability and stability in service.

The NSI824x series adopts the capacitive isolator technology, where the digital signal is modulated by the RF carrier generated by the internal oscillator on the transmitter side, then transmitted via capacitive isolator and demodulated on the receiver side. It’s especially noted that the proprietary Adaptive OOK® modulation technology from NOVOSENSE is used, which delivers many benefits including high noise resistance and low EMI.