Buck DC to DC Converter vs. Linear Regulator

This design shows how an abstract model of a DC to DC converter can be used to make higher level design trade-offs, before committing to or investing engineering effort in detailed circuit design. In this case, a comparison is made between a buck converter and a linear voltage regulator. A model was calibrated to represent an MC7805B, a 5V and 1A Linear Regulator, using only information supplied in the datasheet.

The model of the buck converter uses a “state-average” abstraction (i.e. the actual switching effect is removed by averaging), so that it simulates very quickly. It can be used for iterative compensator tuning, and also supports small-signal AC analysis. The efficiency and performance of both voltage conversion methods can be analyzed and compared. Performance metrics include line and load transient response, as well as both time-domain and frequency-domain ripple rejection simulations. The results provide the information needed to make key design trade-offs.

Mike Donnelly's picture



Mike Donnelly

Joined November 8, 2013
Design added Wednesday, January 14, 2015 | 6:51 am PST