NCP5006 ON Semiconductor, NCP5006 Datasheet - Page 9

• Manufacturer Part Number: NCP5006
• Description: Compact Backlight LED Boost Driver
• Manufacturer: ON Semiconductor

Output Load Drive
shall operate the NCP5006 in the continuous output current
mode. Such a mode is achieved by using and external
reservoir capacitor (see Table 1) across the LED.
diodes shall be within the maximum ratings specified for
these devices. Of course, pulsed operation can be achieved,
due to the EN signal Pin 4, to force high current into the
LED when necessary.
100
100
In order to optimize the built−in Boost capabilities, one
At this point, the peak current flowing into the LED
90
80
70
60
50
40
30
20
10
90
80
70
60
50
40
30
20
10
0
0
2.50
2.50
Figure 10. Overall Efficiency vs. Power Supply @
Figure 12. Overall Efficiency vs. Power Supply @
4 LED/15 mA
5 LED/4 mA
3 LED/15 mA
Yield = f(V
Yield = f(V
3.00
3.00
5 LED/15 mA
3 LED/4 mA
I
out
bat
I
bat
out
3.50
3.50
) @ I
) @ I
= 4.0 mA, L = 22 mH
= 15 mA, L = 22 mH
out
4 LED/4 mA
out
V
Vbat (V)
bat
4.00
4.00
= 4.0 mA/L
= 15 mA/L
(V)
2 LED/4 mA
TYPICAL OPERATING CHARACTERISTICS
4.50
4.50
2 LED/15 mA
out
out
= 22 mH
= 22 mH
5.00
5.00
http://onsemi.com
5.50
5.50
NCP5006
9
(see Figure 9), provides a rectification and filtering
function.
•
100
100
90
80
70
60
50
40
30
20
10
90
80
70
60
50
40
30
20
10
The Schottky diode D1, associated with capacitor C2
When a pulse−operating mode is acceptable:
A PWM mode control can be used to adjust the output
current range by means of a resistor and a capacitor
connected across FB pin. On the other hand, the
Schottky diode can be removed and replaced by at
least one LED diode, keeping in mind such LED shall
sustain the large pulsed peak current during the
operation.
0
0
2.50
2.50
Figure 11. Overall Efficiency vs. Power Supply @
Figure 13. Overall Efficiency vs. Power Supply @
4 LED/20 mA
2 LED/10 mA
3 LED/20 mA
Yield = f(V
Yield = f(V
3.00
3.00
4 LED/10 mA
5 LED/20 mA
I
out
I
bat
bat
out
3.50
3.50
) @ I
= 10 mA, L = 22 mH
) @ I
= 20 mA, L = 22 mH
5 LED/10 mA
out
out
V
Vbat (V)
bat
4.00
4.00
= 10 mA/L
= 20 mA/L
(V)
4.50
4.50
2 LED/20 mA
3 LED/10 mA
out
out
= 22 mH
= 22 mH
5.00
5.00
5.50
5.50