MP3305 MPS, MP3305 Datasheet - Page 9

• Manufacturer Part Number: MP3305
• Description: 36v, 1.3a, Step-up White Led Driver With High Frequency True Pwm Dimming & Adjust Ovp
• Manufacturer: MPS

3.3V -18V
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.
MP3305 Rev. 0.9
12/18/2009
4.5V-18V
GND
TYPICAL APPLICATION CIRCUITS
Figure 4 — Driving 27 WLEDs (9 WLEDs in Series and 3 Strings Paralleled) with 3.3V-18V Input Voltage
EN
GND
VIN
VIN
EN
10uF
25V
C1
Bias Circuit
Optional
MP3305 –36V, 1.3A, STEP-UP WHITE LED DRIVER WITH HIGH FREQUENCY TRUE PWM DIMMING & ADJUST OVP
C1
10uF
25V
ZENER
5.6V
Figure 5 — Wide Input Voltage Step-up Converter for 27 WLEDs
ZENER
for High Input Voltage
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
Required Bias Circuit
D2
7.5
5.6V
D2
( 9 WLEDs in Series and 3 Strings Paralleled )
Q2
2N3904
0.1uF
C3
0.1uF
25V
10uH
50V
L1
C3
5
EN
© 2009 MPS. All Rights Reserved.
GND
5
8
8
10uH
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IN
L1
EN
GND
MP3305
3
PGND
IN
MP3305
3
2
PGND
SW
1
ISET
OVP
2
LED
SW
1
ISET
B0540
OVP
LED
6
7
4
D1
4
6
7
B0540
D1
R3
R4
C4
330nF
50V
C2
330nF
50V
LED-
LED+
LED+
LED-
9