Datasheet

TPS28225

TPS28226

SLUS710C –MAY 2006–REVISED APRIL 2010

www.ti.com

The plots show that the R

DS(on)

at 5-V drive is substantially larger than at 7 V and above that the R

DS(on)

curve is

almost flat. This means that moving from 5-V drive to an 8-V drive boosts the efficiency because of lower R

DS(on)

of the MOSFETs at 8 V. Further increase of drive voltage from 8 V to 12 V only slightly decreases the conduction

losses but the power dissipated inside the driver increases dramatically (by 125%). The power dissipated by the

driver with 5V, 8V and 12V drive as a function of switching frequency from 400kHz to 800kHz. It should be noted

that the 12-V driver exceeds the maximum dissipated power allowed for an SOIC-8 package even at 400-kHz

switching frequency.