The LTC3375 provides some additional tools for source suppression. The slew rate of the switch on the buck regulators can be adjusted, via I 2C. Since the buck regulators are synchronous, both the fall and the rise time are then increased. Figure 2 and Figure 3 show plots of switching with full speed and reduced speed (respectively) rise and fall times:
Click on image to enlarge
Figure 3 is a plot of switching with reduced speed rise and fall times:
Linear regulator controller
The linear controller may be run off of the 12V battery supply, supplying a relatively small amount of current. The output power of the LDO is dependent on the components used. It can be sized to provide 50mA @ 20V. This enables to supply power to any “Always On” circuitry in an automotive infotainment system, while the LTC3375 consumes 11uA of current in its powered down state. In this example, it eliminates the need for a separate low power supply to maintain the system memory. See Figure 4 for details.
Immunity to extreme voltage excursions
Another hurdle for automotive electronics is the dramatic changes in battery