STMicroelectronics LED7707, Application Note, Page: 5 / 17

AN2810 LED7707 demonstration board
Doc ID 14893 Rev 1 5/17
2 LED7707 demonstration board
The LED7707 demonstration board has been designed to manage six strings of 8 to 10
white LEDs each.
Table 1 summarizes the board features and Figure 2 shows the LED7707 demonstration
board schematic. The input voltage range is limited to 32 V because of the 35 V rated input
capacitor. An extended operating input voltage range (up to 36 V) can be achieved by using
a 50 V-rated MLCC.
Figure 2. LED7707 demonstration board schematic
Table 1. LED7707 performance summary
Parameter Conditions Value
Minimum input voltage 6 V
Maximum input voltage 32 V
Output voltage V
IN
<V
BOOST
<36 V
Output OVP threshold R
1
=510 k
Ω ,
R2=16 k
Ω
38 V
Internal MOSFET OCP R
7
=360 k
Ω
3.3 A
Boost section switching frequency
FSW pin to AVCC 660 kHz
FSW pin to R
5
=330 k
Ω
825 kHz
Minimum dimming on-time 400 Hz<F
DIM
<20 kHz 10 µs
Output current (each row)
R
6
=24 k
Ω
75 mA
Output current accuracy ±2%
Efficiency
V
IN
=12V , V
BOOST
=34 V,
F
SW
=660 kHz
91%
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