Datasheet

TI: 700kHz
Ind: 700kHz
5 10 15 25 35
75
90
20 30
80
85
Efficiency − %
C
L
− Load Currnt − A
TI: 800kHz
Ind: 800kHz
5 10 15 25 35
75
90
20 30
80
85
Efficiency − %
C
L
− Load Currnt − A
Rdson @
Vg = 5V
Rdson @
Vg = 7V
Rdson @
Vg = 5V
Rdson @
Vg = 7V
400 500 700 800
0.0
1.5
2.0
600
0.5
1.0
DRIVE LOSS
vs
SWITCHING FREQUENCY
F
SW
− Switching Frequency − kHz
12−V
Estimation
SOIC−8
Package
Limit at 45°C
8−V
TPS28225
5−V
Ind. Std.
D
L
− Drive Loss − W
TPS28225
TPS28226
www.ti.com SLUS710C –MAY 2006–REVISED APRIL 2010
EFFICIENCY EFFICIENCY
vs vs
LOAD CURRENT LOAD CURRENT
Figure 34. Figure 35.
When using the same power stage, the driver with the optimal drive voltage and optimal dead time can boost
efficiency up to 5%. The optimal 8-V drive voltage versus 5-V drive contributes 2% to 3% efficiency increase and
the remaining 1% to 2% can be attributed to the reduced dead time. The 7-V to 8-V drive voltage is optimal for
operation at switching frequency range above 400kHz and can be illustrated by observing typical R
DS(on)
curves
of modern FETs as a function of their gate drive voltage. This is shown in Figure 36.
Figure 36. R
DS(on)
of MOSFET as Function of V
GS
Figure 37. Drive Power as Function of V
GS
and F
SW
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