Chips meant for service in satellites must be designed for radiation hardness; otherwise, the device is subject to glitches due to the incidence of ionized particles. To meet those requirements, Sondrel is designing its first radiation-hardened (Rad-Hard) chip for a customer. That chip, which is due for tape-out shortly, is a satellite modem IC.
Graham Curren, Sondrel’s CEO, said, “The customer came to us because quality and reliability are paramount for a chip that goes into space. It must work correctly all the time as you can’t get an engineer to swap it over if a problem occurs. Our work on functional safety for chips that are used in mission-critical applications in cars and planes means we understand how to design for all eventualities. It takes really outside-the-box thinking to imagine what could possibly go wrong and design solutions should that occur. The engineers really enjoy the brainstorming sessions to come up with unusual scenarios and solving them as it stretches their imaginations in a very rewarding way. In pre-COVID days, those session were like a party game with everyone chipping in ideas over pizzas.”
According to Kirthi Kishore, Staff Engineer Level 3 at Sondrel’s office in Hyderabad, India, “Neither the process nor the cells and IP are specially designed to be radiation hardened. The key is to build in redundant logic in case of damage or to take over while an affected part is rebooted. In the case of the ARM 853 processor at the heart of the chip, the design has to ensure that the processor reboots correctly if a hard reset is needed due to a radiation event.”
The satellite-modem design is for GlobalFoundries’ 22-nm process, which is less susceptible to radiation than smaller process nodes. It has an area of 200 mm2 with 15 IP blocks with over 46 million instances.