STMicroelectronics LED7707, Application Note

Page: 3 / 17

AN2810 List of figures
Doc ID 14893 Rev 1 3/17
List of figures
Figure 1. LED7707 demonstration board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 2. LED7707 demonstration board schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 3. Top side component placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 4. Bottom side test points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 5. SW1 (F
SW
) setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Figure 6. SW2 (MODE) setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Figure 7. LED7707 demonstration board and white LED test board assembly . . . . . . . . . . . . . . . . . 11
Figure 8. LED7707 demonstration board test setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 9. LED7707 synchronization setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 10. Efficiency measurement setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 11. Efficiency vs. DIM duty cycle, V
IN
=12 V, 6 rows, 10 white LEDs in series, I
OUT
= 360 mA 15
Figure 12. Efficiency vs. DIM duty cycle, V
IN
=24 V, 6 rows, 10 white LEDs in series, I
OUT
= 360 mA 15