Efficiency; Measured Efficiency, Tps54350 - Texas Instruments SWIFT TPS54350EVM-235 User Manual

2.2 Efficiency

The TPS54350EVM−235 efficiency peaks at load current of about 1 A and V
of 6 V, and then decreases as the load current increases towards full load. For
higher input voltages, quiescent losses are greater and the efficiency peaks
under full load conditions. It is important to consider that this design is
optimized for small size and flexibility and does not reflect the high efficiencies
that are possible for specific applications using the TPS54350. Figure 2−2
shows the efficiency for the TPS54350 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 500 kHz than at lower switching frequencies due to the gate
and switching losses in the MOSFETs.
Figure 2−2. Measured Efficiency, TPS54350

EFFICIENCY

vs
OUTPUT CURRENT
100
95
V I = 12 V
V I = 6 V
90
85
80
75
V I = 18 V
70
65
60
55
50
0 1 2
I O − Output Current − A
3 4
Test Setup and Results
Efficiency
I
2-3