MP3304 MPS, MP3304 Datasheet - Page 10

• Manufacturer Part Number: MP3304
• Description: The Future Of Analog Ic Technology
• Manufacturer: MPS

TYPICAL APPLICATION CIRCUITS
In order to improve the MOSFET on-resistance at low input voltage and make the chip compatible for
high input voltage, the additional bias circuit should be used.
MP3304 Rev. 0.91
4/19/2010
Figure 6 — Driving 27 WLEDs (9 WLEDs in Series and 3 Strings Paralleled) with 3.3V-18V Input Voltage
3.3V -18V
4.5V-18V
GND
EN
GND
VIN
VIN
EN
10uF
25V
C1
MP3304 –36V, 1.3A, STEP-UP WHITE LED DRIVER WITH HIGH FREQUENCY TRUE PWM DIMMING
Bias Circuit
Optional
C1
10uF
25V
Figure 7 — Wide Input Voltage Step-up Converter for 27 WLEDs
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
ZENER
ZENER
5.6V
7.5
for High Input Voltage
Required Bias Circuit
D2
5.6V
D2
( 9 WLEDs in Series and 3 Strings Paralleled )
Q2
2N3904
0.1uF
C3
0.1uF
25V
10uH
50V
L1
C3
5
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EN
GND
5
8
8
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10uH
MP3304A
IN
L1
EN
GND
3
PGND
MP3304A
IN
3
2
(continued)
PGND
SW
1
ISET
2
LED
SW
1
ISET
B0540
LED
6
7
D1
6
7
B0540
D1
C4
330nF
50V
C2
330nF
50V
LED+
LED-
LED-
LED+
10