Datasheet

Light-load performance AN4165
18/37 Doc ID 023661 Rev 1
9 Light-load performance
The input power of the converter has been measured in no load condition for different input
voltages and the results are given in
Ta bl e 7
.
In version 4.0 of the Code of Conduct the power consumption of the power supply when it is
not loaded is also considered. The criteria for compliance are given in the table below:
Table 8. Energy consumption criteria for no load
The power consumption of the STEVAL-ISA111V1 board is about ten times lower than the
Code of Conduct (version 4) limit. Even if this performance seems to be disproportionally
better than the requirements, it is worth noting that often AC-DC adapter or battery charger
manufacturers have very strict requirements about no load consumption and when the
converter is used as an auxiliary power supply, the line filter is often the main line filter of the
entire power supply which considerably increases standby consumption.
Even if the Code of Conduct (version 4) program does not have other requirements
regarding light load performance, in order to give more information the input power and
efficiency of the demonstration board in two other light load cases is also shown.
Ta ble 9
and
Ta ble 10
show the performance when the output load is 25 mW and 50 mW
respectively.
Table 7. No load input power
V
IN
[V
AC
]P
IN
[mW]
90 13.4
115 14.4
150 16.1
180 18.0
230 22.2
265 24.9
Nameplate output power (Pno) Maximum power in no load for AC-DC EPS
0 W P
no
50 W < 0.3 W
50 W < P
no
< 250 W < 0.5 W
Table 9. Light load performance at P
OUT
= 25 mW
V
IN
[V
AC
]P
OUT
[mW] P
IN
[mW] Efficiency (%)
90 25 44.9 55.7
115 25 46.3 54.0
150 25 49.1 50.9
180 25 51.5 48.5
230 25 55.0 45.5
265 25 59.0 42.4