NCP5008_06 ONSEMI [ON Semiconductor], NCP5008_06 Datasheet - Page 12

• Manufacturer Part Number: NCP5008_06
• Description: Backlight LED Boost Driver
• Manufacturer: ONSEMI [ON Semiconductor]

Output Load Drive
one shall operate the NCP5008/NCP5009 in the continuous
output current mode. Such a mode is achieved by using and
external reservoir capacitor (preferably a low ESR ceramic
type) across the LED as depicted in Figures 22, 23, 24, 25,
and 26.
related pin 2 can be either left open or connected to V
but must not be grounded on the NCP5009 version only.
parameters:
In order to make profit of the built−in Boost capabilities,
Using an extra photo sensor is not mandatory and the
At this point, the designer must carefully analyze two
1. The output voltage must be limited to 15 V
maximum. It’s the designer responsibility to
make sure that spike voltages beyond the
Vcc
NPN−PHOTO
GND
GND
Figure 22. Basic DC Current Mode Operation in REMOTE Control
Q1
30 k
R1
GND
V
bat
TYPICAL APPLICATION CIRCUIT
1
2
4
4
3
5
GND
NCP5008, NCP5009
U1
I
PHOTO
CS
CLK
NCP5009
VBIAS
ref
http://onsemi.com
LED
D1
bat
,
12
LED
D2
2.2 mF/16 V
LOCAL
provides a rectification and filtering function.
•
•
GND
The Schottky diode D5, associated with capacitor C2,
When a pulse−operating mode is acceptable:
The LEDs brightness can be controlled in LOCAL
mode with a PWM on CS pin as depicted in Figure 24.
Or the Schottky can be removed and replaced by at
least one LED diode as depicted in Figure 23.
V
C2
bat
L1
L2
2. The peak current flowing into the LED diodes
LED
D3
maximum rating will not exist across pin 8 and
ground. Depending upon a specific application
(V
voltage clamp could be necessary.
shall be within the maximum ratings specified for
these devices.
10
8
7
9
6
bat
GND
voltage, PCB layout…), using an external
V
LED
D4
bat
L1
22 mH
10 mF/6.3 V
C1
D5
GND
MBR0520