New digital isolators with superior radiation performance for SmallSats in LEO

Renesas Electronics has introduced two plastic packaged, radiation-tolerant digital isolators that provide the highest isolation protection (2,500V_RMS) from high voltage spikes in power supply stages and serial communications interfaces used in LEO SmallSats. Private 'New Space' companies intend to launch thousands of SmallSats forming large constellations that work in multiple LEO planes. SmallSat mega-constellations offer ubiquitous broadband IoT communications anywhere across the globe, and Earth observation high-resolution imaging for air, sea, and land asset tracking. The passive input ISL71610M and active input ISL71710M provide excellent performance across key electrical specifications, incorporating isolation voltage, data rate, propagation delay, quiescent current, common mode transient immunity, and dynamic current. The company’s GMR digital isolators are perfect alternatives for optocouplers that are susceptible to cloudy optics from TID radiation. Both GMR isolators also out-perform transformer-based digital isolators that encounter EMI due to radiated emissions from edge and dipole radiation. The GMR digital isolators are characterisation tested at a TID of up to 30krads(Si), and for SEE at a LET of 43MeV•cm2/mg. “The ISL71610M and ISL71710M use a GMR inductive structure that is inherently immune to radiation effects, and build on Renesas’ six decades of spaceflight experience,” said Philip Chesley, vice president, Industrial Analog and Power Business Division, Renesas Electronics Corporation. “GMR makes our space-grade digital isolators more desirable than optical-based designs, and Renesas’ radiation-tolerant plastic flow provides the optimal cost versus radiation performance in comparison to Class V isolators.”