REV. 0

ADP3204

–15–

turned off. During the common off time of all channels, their

currents are averaged and compared to the lower threshold.

When the averaged channel current reaches the lower threshold,

the hysteretic comparator changes state again, and turns on the

control FET of the next channel, as selected by the phase

splitter logic. This control concept ensures that the peak

currents of all channels will be the same, and therefore the

CS1

CS2

CS3

PHASE 1

PHASE 2

PHASE 3

L1

L2

L3

PHASE

SPLITTER

HYSTERETIC

CORE

COMPARATOR

CURRENT

SENSE MUX

LOAD

OUT 3

OUT 2

OUT 1

Figure 4. 3-Phase Modified Hysteretic Regulator with ADOPT

MathCAD is a trademark of MathSoft.

channel currents will be perfectly balanced. The ADOPT

compensation can be used the same way as in the single-phase

version discussed previously.

Since due to second-order effects, the detailed design of a

multiphase converter with the ADP320x family is rather

complex, a design aid using MathSoft’s MathCAD™ program

has been developed. Please contact ADI for further information.