AN4007 datasheet(31/33 Pages) STMICROELECTRONICS

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AN4007

Conclusions

Doc ID 022455 Rev 2

31/33

Conclusions

A 15 W wide range single-output flyback converter using the new VIPER37LE has been

introduced and the results given.

The presented flyback converter is suitable as an external adapter or as an auxiliary power

supply in consumer equipment. Special attention was paid to low load performance and the

bench results are good with very low input power in light load condition.

The efficiency performances were compared with the requirements fixed by both EC CoC

and DoE US EISA 2007 programs for external AC/DC adapters with very good results, the

measured Active mode efficiency is always higher with respect to the minimum required.

Demonstration tools and documentation

The VIPER37LE demonstration board order code is: EVLVIP37LE5V3A.

Further information about this product is available in the VIPER37 datasheet at www.st.com.

Table 6.

Temperature of key components (Tamb=25 °C, emissivity=0.95 for all

points)

Point

Reference

T [°C] at 115 VAC

T [°C] at 230 VAC

IC (VIPER37LE)

61.2

63.4

D1 (Transil clamp)

82.8

81.6

D2 (output diode)

44.1

45.0

TF (flyback transformer)

67.3

70.0

NTC (inrush limiter)

54.1

41.6

AN4007 Datasheet(PDF) 31 Page - STMicroelectronics