Datasheet

Measurements UM0984
16/25 Doc ID 17812 Rev 2
Figure 7. Efficiency at full load (1 A) vs. input voltage
The output voltage efficiency depending on the output current of the 12 V output is displayed
in Figure 6. The 3.3 V output was not loaded for this measurement.
Figure 7 shows the efficiency of the SMPS at full load applied on the 12 V output (1 A, 3.3 V
output not loaded) depending on the different input voltages. A drop of efficiency at low input
voltage is mainly caused by an increase of the losses of the input inrush resistor and CMC.
The efficiency was calculated as the ratio between the output power and input power. The
input power was directly measured by power analyzer NORMA 4000. The output power was
calculated as the product of the output current and output voltage. The output voltage was
measured on the output connector by multimeter KEITHLEY 2000 and the current was
measured by multimeter FLUKE 189.