| The number of output channels managed by junction boxes is rapidly increasing. Controlling all these loads, including PWM and synchronous diagnosis, requires powerful microcontrollers, bulky software, and many I/Os. STMicroelectronics offers a multiplexer interface between the microcontroller and high-side drivers, the L99PD08, which controls and monitors eight driver channels via the SPI. The circuit also provides phase shifted PWM and synchronous diagnosis and removes a heavy software load from the microcontroller. Limp-home functions are also embedded, making system fail-safe management easy. The circuit is optimized to drive STMicroelectronics' M0-5 and M0-5E advanced high-side driver family.