austriamicrosystems extends its high-voltage CMOS technology toward power grid apps

UNTERPREMSTAETTEN, AUSTRIA: austriamicrosystems’ Full Service Foundry business unit announced at the GSA (Global Semiconductor Alliance) Semiconductor Ecosystems Summit a further extension of its 0.35 µm High-Voltage CMOS technology portfolio. By introducing special inter-metal dioxide (IMD) layers, galvanic isolation is significantly improved to over several hundred volts.

In an increasing number of complex analog/mixed-signal applications, such as switching-mode-power-supplies and motor drivers, two individual ICs must operate together, even though they operate at significantly different voltage levels. In order to achieve synchronized performance, isolated communication between these two isolated ICs is required to enable the exchange of information.

At present, isolation is often achieved with an optocoupler placed between the two communicating circuits. The newly developed galvanic isolation process allows the designer to skip the optocoupler and directly integrate the communicating circuits within one single package (i.e. dual-die solution), as long as one IC features austriamicrosystems’ special IMD layers.

“Our new IMD layers allow us to achieve isolation voltage ratings beyond 600 Vrms”, says Dr. Martin Schrems, director of Process Development & Implementation at austriamicrosystems. “We’ve derived these ratings without changing our standard bill of materials, which is established in our leading edge 0.35 µm High-Voltage CMOS process, but instead utilized a low stress oxide that gives us the required IMD thickness.”

“Having developed six generations of high-voltage CMOS processes, the extension of our leading edge H35 specialty process towards voltages beyond 200 V is a logical step in our continuous efforts to deliver best-in-class analog foundry services and technologies to our customers," states Thomas Riener, senior VP and GM of austriamicrosystems' Full Service Foundry business unit. “As most advanced High-Voltage CMOS manufacturers, we want to offer our customers the possibility to expand their product portfolio towards motor controllers and power grid applications, which certainly constitute an attractive market due to worldwide sustainability initiatives.”

Isolated communications may either be based on inductive coupling between two coils or on capacitive coupling of two capacitors. In both cases the isolation rating is determined by the metal layers being used to form these passive elements. If ultra-high isolation levels (>1000 V) are needed, an isolation cascade may be considered using IMD isolation on both dies constituting the integrated system.

austriamicrosystems’ galvanic isolation process H35B4V1 is now included in the analog/mixed signal high performance process design kit.