🚀 Revolution in Industrial Automation: Solid-State Isolation!

[Elif Özaksu]

💡 Space-Saving Solution: Next-Generation Isolation from Infineon​

Infineon is introducing a new space-saving technology to replace traditional electromechanical relays in industrial automation systems: Coreless transformer-based solid-state isolators (SSI). The ISSI20BxxF series offers a compact hardware solution to modernize photovoltaic and electromechanical relay systems, especially in designs with limited space.

⚡ High Efficiency and Powerful Driving Capability​

This new architecture provides highly efficient power and signal transfer for various industrial automation applications such as solid-state relay modules, programmable logic controller (PLC) inputs and outputs. Thanks to proprietary coreless transformer technology, the ISSI20BxxF series eliminates the need for a dedicated isolated gate supply by transferring both operational signals and power across an isolation barrier to drive external power switches.

This architectural approach offers a higher output drive capability compared to traditional photovoltaic isolator (PVI) solutions, allowing engineers to match the isolator with a wider range of external power switches based on specific load requirements. The ISSI20B02F, ISSI20B03F, and ISSI20B11F variants, housed in a PG-DSO-8 150 mil package, bring solid-state isolation to extremely confined spaces while maintaining the physical footprint of existing PVI solutions. By replacing electromechanical relays (EMRs), they eliminate mechanical wear, contact bounce, and electrical arcing, thereby ensuring silent operation and extending service life for high-cycle switching applications.

🛡️ Integrated Protection and Safety Certifications​

To enhance system robustness and reduce reliance on external discrete circuits, the isolator family integrates multiple hardware-level protection mechanisms, such as overcurrent protection, overtemperature protection, fast fault shutdown, and latching capabilities. For environments with particularly demanding switching requirements, selected device variants include dynamic Miller clamp and fast turn-off functions.

To ensure compliance with industrial safety protocols, all three devices offer a 3 kVrms isolation rating and 4 mil physical creepage distance, verified with UL 1577 certification for basic isolation requirements. The resulting architecture supports a wide range of applications, from automated test equipment to laboratory DC power supplies, telecommunication infrastructure, and low-voltage building automation.

🔍 Inductive Superiority Over Optical Isolation​

In the component isolation market, traditional photovoltaic isolators and relays, such as the Broadcom ASSR series or standard optical PhotoMOS relays, rely on optical coupling using light-emitting diodes (LEDs) and photovoltaic receiver arrays. While effective for basic galvanic isolation, optically coupled PVIs typically provide limited microamp-level gate drive currents, which restricts the switching speed of large, high-capacitance external MOSFETs and leads to long-term current transfer ratio (CTR) degradation as the LED ages.

In contrast, the ISSI20BxxF leverages inductive coreless transformer technology, using principles similar to the high-speed digital isolation architectures found in Texas Instruments' ISO series or Analog Devices' iCoupler technology. By utilizing an inductive transfer mechanism instead of optical, this solid-state isolation approach provides significantly higher gate drive currents without being susceptible to optical degradation over time. This measurable difference in drive power allows industrial automation circuits to achieve faster switching cycles and reliably operate with external power transistors that have heavier gate charge profiles.