Silicon Labs and National Semiconductor Isolated dc-dc SMPS Reference Design

Featuring Silicon Labs’ Si8420 digital isolator and National Semiconductor’s LM5035C pulse-width modulation (PWM) controller the isolated dc-dc converter evaluation board provides power converter designers with a highly efficient 100 W reference design in a quarter-brick form factor. The evaluation board reduces the time required for product characterization and design adaptation to the customer’s specific requirements.The reference design demonstrates a viable 36 to 75 V input half-bridge converter for power module or embedded power applications. The design survives input transients up to 100 V as commonly required in communications equipment and protects the power distribution system with hiccup-mode fault protection.

Silicon Labs Si8420 Digital Isolator

Silicon Labs’ family of  Si84xx digital isolators employs digital RF technology to communicate data across an isolation barrier. Using the Silicon Labs Si8420 digital isolator in place of pulse transformers eliminates numerous design issues such as duty cycle limitations and non-monotonic decay of output during shutdown. In addition, use of digital isolators improves efficiency and saves board space by eliminating the need for pulse transformers.

National Semiconductor LM5035C PWM Controller

National Semiconductor’s LM5035C PWM controller includes integrated 2-amp half-bridge gate drivers and SyncFET outputs that control the secondary side synchronous rectifier MOSFETs through the Si8420 digital isolator. For more information on the reference design, please visit National Semiconductor.