MP3385A

4-String, 80V Output,

WLED Controller with I

MP3385A Rev. 1.01

www.MonolithicPower.com

1

8/29/2017

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© 2017 MPS. All Rights Reserved.

The Future of Analog IC Technology

DESCRIPTION

The MP3385A is a step-up controller with four

regulated current channels designed to drive

WLED arrays for mid- and large-sized LCD

panel backlighting applications.

The MP3385A uses peak-current mode and

PWM control architecture for system loop

regulation. The MP3385A drives an external

MOSFET to boost up the output voltage from a

4.5V-to-33V input supply.

that can flexibly set operation and protection

modes, including dimming mode, dimming

current and dimming ratio, OCP, OVP, LED

short

protection

threshold,

and

switching

frequency. For easy application use and board

debugging, the MP3385A detects and disables

the unused LED strings automatically during

start-up to avoid charging the output to the OVP

threshold.

The MP3385A achieves 1.8% current matching

between each string. The low regulation voltage

on the LED current sources improves efficiency

and reduces power loss to achieve a higher

current output.

The MP3385A supports analog, PWM, and

combined analog and PWM dimming modes to

meet different application requirements. Full

protection

features

include

over-current

protection (OCP), over-temperature protection

(OTP), under-voltage protection (UVP), over-

voltage protection (OVP), LED short/open

protection, and inductor/diode short protection.

The MP3385A is available in a QFN-20

(4mmx4mm) package.

FEATURES

 4-String, Max 300mA/String WLED Driver

 4.5V to 33V Input Voltage Range

 80V ABS Rating for Each String

 1.8% Current Matching Accuracy for Each

String

 Unused Channel Auto-Detection Function

during Start-Up

 100kHz-900kHz Programmable Switching

Frequency

Interface

o

Direct PWM Dimming Mode

o

Internal Fixed 23kHz PWM Dimming

o

Analog Dimming Mode by Input Pulse

o

o

Mixed Dimming Mode by Input Pulse

o

 2%-100% Programmable Full Scale Current

with 8-Bit Resolution

 0%-100% LED Dimming Range with 10-Bit

Resolution for Internal Dimming Mode

 Cascading Capability with a Single Power

Source

 18V to 80V Over-Voltage Protection (OVP),

2V/Step

 0.15V to 0.5V Latch-Off/Recoverable Over-

Current

Protection

(OCP)

Threshold,

50mV/Step

 Recoverable Thermal Shutdown Protection

APPLICATIONS

 Desktop LCD Flat Panel Displays

 All-in-One PCs

 2D/3D LCD TVs

All MPS parts are lead-free, halogen-free, and adhere to the RoHS directive. For

MPS green status, please visit the MPS website under Quality

Assurance. “MPS” and “The Future of Analog IC Technology” are registered

trademarks of Monolithic Power Systems, Inc.