Efficiency and no-load measurements

AN3093

12/29

Doc ID16539 Rev 1

Figure 9.

Efficiency vs. output power

should be calculated as the average of the efficiency at 25%, 50%, 75% and 100% of the

rated load.

The input power without load has also been measured and as indicated in Table 6, for both

The proposed adapter using the ALTAIR05T-800 meets the most restrictive worldwide

standards for efficiency and power consumption at no-load (European Code of Conduct,

150 mW).

3.1

Standby optimization: tips for reducing standby

consumption

When light loaded or in no-load condition, most of the losses are switching losses, which are

almost proportional to the switching frequency. It should be considered that even if no

external load is connected to the power supply, some power needs to be processed in order

to sustain the operation of the ALTAIR05T-800 and some is also dissipated on the bleeder

resistor at the secondary side.

Basically, when the converter switches to burst mode operation, the lower the load, the lower

the average switching frequency. So, the burst mode operation of the ALTAIR05T-800

Table 6.

Standby consumption

54 mW

75 mW