AN4376 datasheet(18/37 Pages) STMICROELECTRONICS

Part #	AN4376

Description	10 W wide range non-isolated high power factor LED driver using HVLED815PF

PDF	37 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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18 / 37 page

Measurement results

AN4376

18/37

DocID025380 Rev 1

6.5

Driver efficiency at nominal load

The LED driver efficiency is up to 89%.

Figure 15. Efficiency vs. AC line voltage at nominal load

Efficiency at Japanese range is around 87% and increases to 88% at European voltage.

6.6

LED driver performance varying the number of LEDs

The performance of the LED driver has been collected varying the LED number and as

consequence the string voltage drops after a thermal warm-up (T = 1 h). In Table 2 are

shown the descriptions of the loads applied and corresponding to a total voltage drop after

a warm-up:

Table 2. LED string voltage specification

LED number

String voltage drop

Variation respect to nominal

voltage

23 LEDs

68.3 VDC

- 2.4%

25 LEDs

74.0 VDC

+ 5.7%

21 LEDs

62.3 VDC

- 11%

18 LEDs

53.2 VDC

- 24%

AN4376 Datasheet(PDF) 18 Page - STMicroelectronics