This reference design uses a tiny automotive buck converter to support a 5-V rail by input voltage range 6.5-V up to 32-Vpk surge. The layout and design are optimized to pass CISPR-25. The design is equipped with a two-stage input filter to minimize conducted emissions and a solid ground plane to attenuate radiated emissions in short wave range. Power stage capacitors are routed back-to-back to minimize parasitic inductances at forward and freewheeling loop. Highlights of this design are a cost-effective two-layered board (typical for automotive cluster and display applications), single-side assembly and keeping the solid ground plane to pass EMI.
- Cost-efficient low power automotive 5 V supply delivers up to 15-W output power
- Two-stage input filter reduces conducted emissions due to reflected ripple
- Small passives due to high switching frequency and integrated FETs allow small form factor
- Two-layer board with single side assembly on top simplifies manufacturing
- Solid ground plane on bottom side realizes better EMC performance