Texas Instruments TPS54673EVM-225, Руководство пользователя, Страница: 19 / 42

Efficiency
2-3 Test Setup and Results
2.2 Efficiency
The TPS54x73EVM-225 efficiency peaks at load current of about 1 A to 2 A,
and then decreases as the load current increases towards full load. The
efficiency shown in Figure 2–2 is for the TPS54673 and the TPS54873 at an
ambient temperature of 25
°
C. The efficiency is lower at higher ambient
temperatures, due to temperature variation in the drain-to-source resistance
of the MOSFETs. The efficiency is slightly lower at 700 kHz than at lower
switching frequencies, due to the gate and switching losses in the MOSFETs.
Figure 2–2. Measured Efficiency, TPS54673
50
55
60
65
70
75
80
85
90
95
100
0 1 2 3 4 5 6 7
Efficiency
–
%
EFFICIENCY
vs
OUTPUT CURRENT
IO – Output Current – A
VI = 5 V, VO = 2.5 V
VI = 3.3 V, VO = 2.5 V