MP3388 Datasheet, PDF (1/14 Pages) Monolithic Power Systems – 50V, 8-String White LED Driver

The Future of Analog IC Technology
MP3388
50V, 8-String White LED Driver
DESCRIPTION
The MP3388 is a step-up converter with
8-channel current sources designed for driving
the white LED arrays for large size LCD panel
backlighting applications.
The MP3388 uses current mode, fixed frequency
architecture. The switching frequency can be
selected at 1.25MHz or 625kHz. It generates an
output voltage up to 50V from a 4.5V to 25V input
supply. The MP3388 independently regulates the
current in each LED string to the user programmed
value set by an external current setting resistor.
The MP3388 applies 8 internal current sources in
each LED string terminal to achieve a current
balance of 3% regulation accuracy between
strings. Its low 600mV regulation voltage on LED
current sources reduces power loss and improves
efficiency.
The MP3388 features external PWM dimming or
DC input PWM dimming, which allows the flexible
control of the backlighting luminance. The dimming
PWM signal can be generated internally, and the
dimming frequency is programmed by an external
setting capacitor.
FEATURES
• High Efficiency and Small Size
• 4.5V to 25V Input Voltage Range
• 50V Maximum Step-up Voltage
• Balanced Driver for 8 Strings of WLED
• 3% Current Matching Accuracy Between
Strings
• Selectable Switching Frequency: 1.25MHz or
625kHz
• PWM or DC Input Burst PWM Dimming
• Programmable Over-voltage Protection
• Under Voltage Lockout
• Open and Short LED protection
• Thermal Shutdown
• Small QFN24 (4x4mm) and 28 pin SOIC
packages
• Halogens Free
APPLICATIONS
• Notebook PC
• Small LCD TV
• Handy Terminals Display
• Automotive System and Tablet Computer
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.
TYPICAL APPLICATION
M1
L1
VIN
4.5V~25V
C1
D1
C2
R1
Enable
R2
C3
C4
24
23
22
21
20
19
VCC
1 _EN
VIN COMP VFAULT SW1 SW2
PGND1 ¹⁸
NC 2
OSC
17
PGND2
C5
PWM
DIMMING
3
FSET
4
C6
5
PWMO
GND
MP3388
16
OVP
LED1 ¹⁵
LED2 ¹⁴
6
PWMI
13
LED3
LED8
7
LED7
8
LED6
9
LED5
10
ISET
11
LED4
12
RSET
MP3388 Rev. 1.0
www.MonolithicPower.com
1
12/16/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.