UM0984

Application recommendations

Doc ID 17812 Rev 2

23/25

5.2

Improved efficiency

The measured efficiency is about 84% at full output load and 230 VAC. This value can be

increased by simply changing the output Schottky diode. Please note that the original board

contains an STPS3H100 - 3 A / 100 V Schottky diode. This diode is universal - applicable

also up to 18 V output voltage. If only 12 V output is required, a 60 V Schottky diode can be

used.

An STPS5L60 - 5 A / 60 V Schottky diode in the SMC package was tested. The result

measured on one sample at 230 VAC is displayed in Table 4.

Table 4.

Efficiency using a 60 V Schottky diode

D3

Eff. (%)

VD3 (V) at 305 VAC

STPS3H100

11.80

1.00

84.1

56

STPS5L60

12.15

1.00

86.1

56