The efficiency of this EVM peaks at a load current of about 0.6 A–1 A and then decreases as the load current increases towards full load. Figure 2-1 shows the efficiency for the TPS54331EVM-232 at an ambient temperature of 25°C.

Figure 2-1 TPS54331 Efficiency

Figure 2-2 shows the efficiency for the TPS54331EVM-232 at lower output currents between 0.01 A and 0.20 A at an ambient temperature of 25°C.

Figure 2-2 TPS54331 Low Current Efficiency

The efficiency can be lower at higher ambient temperatures due to temperature variation in the drain-to-source resistance of the MOSFETs.