AN2840 datasheet(14/19 Pages) STMICROELECTRONICS

tên linh kiện	AN2840

Giải thích chi tiết về linh kiện	charger demonstration board based on the VIPER17HN

PDF	19 Pages

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nhà sản xuất	STMICROELECTRONICS [STMicroelectronics]

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14 / 19 page

Conducted noise measurements (pre-compliance test)

AN2840

14/19

Conducted noise measurements (pre-compliance

test)

Figure 18 and Figure 19 provide the results of the conducted emission pre-compliance

measurements performed at maximum nominal voltage (230 VAC) with quasi-peak and

average detection. For conciseness, only the measurements of the worst line wire are

reported. The measurements show a good margin with respect to the limits stated in the

EN55022 CLASS-B specifications.

In comparing figures 18 and 19, it is worth noting that the VIPER17HN frequency jittering

feature makes it possible to spread the switching frequency harmonics spectrum and reduce

the peak values. This is especially evident in the average measurement where a significant

margin is achieved with respect to the limits.

In Figure 20, the conducted emission in average mode is taken at 115 VAC, full load. As the

graph shows even in this condition the measured noise is well below the EN55022 Class-B

limits.

Figure 18.

VIN = 230 VAC – 50 Hz, full

load CE QP measurement

Figure 19.

VIN = 230 VAC – 50 Hz full load

CE average measurement

Figure 20.

VIN = 115 VAC - 60 Hz CE

average measurement

AN2840 bảng dữ liệu(PDF) 14 Page - STMicroelectronics