Description

Galvanically isolated interfaces are a common requirement within industrial devices for safety reasons. In this type of application, a digital isolator is used to galvanically isolate an MCU from a communication transceiver or an ADC.

Digital isolators work at two power domains, using an isolated DC power supply in one domain. The low DC voltage for isolated power domain could be achieved with a small and simple push-pull converter. The push-pull converter is a transformer-isolated topology using two transistors switching in complementary mode.

This application note will present a low cost and low power DC/DC push-pull converter based on the Silego GreenPAK SLG46108 device. The following sections will show how to:

• Generate a complementary PWM with dead time using the programmable delay block.
• Generate a start-up sequence using a pipe-delay block.
• Obtain multiple clock frequencies via an internal oscillator.