AN1439 datasheet(13/17 Pages) STMICROELECTRONICS

13 / 17 page

AN1439

Design specification

13/17

Figure 13.

STEVAL-ISC001V1: load transient (at Vin = 220 Vac: Iout = 0.5 to 2.5 A)

Evaluation board optimization for minimum no-load consumption

Additional optimization steps need to be taken in order for the STEVAL-ISC001V1 to fulfill

the limits set by the 3rd phase of the European code of conduct on efficiency of external

power supplies, which has been active from 01.01.2005. According to this standard, the no-

load consumption must be less than 0.5 W at rated input voltage (220 Vac for European

mains, the 110 Vac of the US mains is not a concern). To have some margin, it is a common

design target to fulfill the specification even at maximum input voltage (264 Vac).

Figure 11.

STEVAL-ISC001V1 behavior upon

short-circuit on the output.

Vin=220 Vac

Figure 12.

STEVAL-ISC001V1 behavior upon

short-circuit on D7. Vin=220 Vac

Ch1: Q1 drain voltage

Ch2: L6565 supply voltage

Ch1: Q1 drain voltage

Ch2: L6565 supply voltage

Ch2: Output voltage

Ch2: Load current

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