Industrial applications often require high speed SPI buses when interfacing to various sensors. These applications may further require galvanic isolation for enhanced robustness. But when designing such an isolated SPI bus, simply choosing a digital isolator based on the guaranteed data rate isn’t sufficient. The propagation delay of the isolator – rather than the data rate – actually constrains the throughput of the interface. However, this isn’t a concern in non-isolated SPI solutions because PCB trace delays are very small relative to the clock period. So, wouldn’t it be great if we could design an isolated SPI interface with minimal speed limitations introduced by the isolators? Isolated SPI could now be run as fast as its non-isolated counterpart and at the same time be simple to design. Read our article to explore an integrated solution that allows isolated SPI to run as fast as 40MHz, while optimizing for power, size, design-time and cost.