MP3389 Datasheet, PDF (1/16 Pages) Monolithic Power Systems – 12–String, Step-up White LED Driver

The Future of Analog IC Technology
MP3389
12–String, Step-up
White LED Driver
DESCRIPTION
The MP3389 is a step-up controller with 12-
channel current sources designed for driving
the WLED arrays for large size LCD panel
backlighting applications.
The MP3389 uses current mode, fixed frequency
architecture. The switching frequency is
programmable by an external frequency setting
resistor. It drives an external MOSFET to boost
up the output voltage from a 5V to 28V input
supply. The MP3389 regulates the current in
each LED string to the programmed value set by
an external current setting resistor.
The MP3389 applies 12 internal current
sources for current balance. And the current
matching can achieve 2.5% regulation accuracy
between strings. Its low 550mV regulation
voltage on LED current sources reduces power
loss and improves efficiency.
PWM dimming is implemented with external
PWM input signal or DC input signal. The
dimming PWM signal can be generated internally,
and the dimming frequency is programmed by
an external setting capacitor.
TYPICAL APPLICATION
VIN
5V~28V
CIN
M1
L1
Enable
DIMMING
CVCC
2 _VIN
3
VCC
C R COMP
COMP
4
COMP
VFAULT ²⁷
26
GAT E
24
ISENSE
5 _EN
NC ²⁸
R OSC
VCC
RBOSC
8 _OSC
PGND ²⁵
1
NC
23
OVP
10
BOSC
22
LED1
C BOSC
MP3389
7 _GND
LED2 ²¹
RSET
6 _DBRT
9
ISET
LED3 ²⁰
19
LED4
11
LED12
18
LED5
12
LED11
17
LED6
13 _LED10
LED7 ¹⁶
14
LED9
15
LED8
D1
COUT
R1
R2
M2
RSENSE
FEATURES
• High Efficiency and Small Size
• 5V to 28V Input Voltage Range
• Balanced Driver for 12 Strings of WLEDs
• Maximum 60mA for Each String
• 2.5% Current Matching Accuracy Between
Strings
• Programmable Switching Frequency
• PWM or DC Input Burst PWM Dimming
• Open and Short LED protection
• Programmable Over-voltage Protection
• Under Voltage Lockout
• Thermal Shutdown
• 28-pin TSSOP and 28-pin SOIC Package
APPLICATIONS
• Desktop LCD Flat Panel Displays
• Flat Panel Video Displays
• LCD TVs and Monitors
All MPS parts are lead-free and adhere to the RoHS directive. For MPS green
status, please visit MPS website under Quality Assurance. “MPS” and “The
Future of Analog IC Technology” are Registered Trademarks of Monolithic
Power Systems, Inc.
MP3389 Rev. 1.04
www.MonolithicPower.com
1
3/27/2013
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
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