Start/Stop dc-dc Converter
Stop/Start (aka Micro Hybrid or Mild Hybrid) technology conserves energy by shutting off the combustion engine when the vehicle is stopped. The engine is automatically re-started when the driver pushed gas pedal or releases the brake pedal. Stop-start technology has become an effective way for automakers to realize economy gains of 5%-10% to existing ICE vehicle models.
The stop/start solution typically consists of three pieces:
- Motor-generator used in place of a conventional alternator that provides the engine start
- Modified battery to withstand numerous starts
- DC-DC converter to provide a stable 12V, preventing vehicle electronics and lighting from glitching during the high current drain at engine start
Silicon Labs provides a cost effective and efficient solution for the dc-dc converter using the Si825x family of programmable digital power controllers. The Si825x includes closed-loop feedback control, system protection and power management functions. The architecture includes a dedicated 50 MIPS DSP-based control loop processor that enables 10MHz control loop updates. As an automotive dc-dc converter, the Si825x adapts quickly and intelligently to changing battery voltages, including loading/unloading transients.
The Si825x family is fully AEC-Q100 qualified to grade 1 (-40°C to 125°C) and available in a 5 mm x 5 mm QFN or 32-pin LQFP.