AN2683 Datasheet, PDF (1/38 Pages) STMicroelectronics – Compact dual output point of load converter

AN2683
Application note
Compact dual output point of load converter
based on the PM6680 step-down controller
Introduction
This application note demonstrates the performance of the PM6680 dual step-down
controller by implementing a two output point of load converter in a small printed circuit
board footprint. Utilizing constant on-time architecture and featuring a no-audio skip mode of
operation, a common bus voltage that ranges between 10 to 16 V_DC is converted to 1.0 V_DC
at 10.5 amps and 1.8 V_DC at 2.5 amps for a total output power level of 15 watts. The unique
no-audio skip feature significantly improves efficiency at light load. Using surface mount
components on both the top and bottom of the circuit board and featuring ceramic output
capacitors, the area needed for the converter measures only 1.0 by 1.25 inches (25.4 by
37.75 mm). The method for component value dimensioning is described along with the
schematic and construction details. Typical efficiencies and functional test data are also
presented.
Figure 1. PM6680 - top and bottom view
April 2008
Rev 1
1/38
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