EV3385-R-00A

4 String WLED Controller With I

Evaluation Board

EV3385-R-00A Rev.1.1

www.MonolithicPower.com

1

5/21/2015

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© 2015 MPS. All Rights Reserved.

The Future of Analog IC Technology

DESCRIPTION

The MP3385 is a step-up controller with 4

regulated current channels designed to drive

WLED arrays for middle and large-size LCD

panel backlighting applications.

The MP3385 uses peak current mode, PWM

control architecture for system loop regulation.

It drives an external MOSFET to boost up the

output voltage from a 4.5V to 33V input supply.

flexibly set the operation and protection modes,

including dimming mode, dimming current and

dimming ratio, OCP, OVP, LED short protection

threshold, and the switching frequency. For

easy application use and board debugging, the

MP3385 detects and automatically disables the

unused LED strings during start-up to avoid

charging the output to the OVP threshold.

The MP3385 achieves 1.8% current matching

between each string. The low regulation voltage

on the LED current sources improves efficiency

and reduces power loss in order to achieve a

higher current output.

The MP3385 supports analog, PWM, and

combined analog and PWM dimming modes to

meet different application requirements. Full

protection features include OCP, OTP, UVP,

OVP,

LED

short/open

protection,

and

inductor/diode short protection.

The MP3385 is available in a QFN-20

4mm x 4mm and a TSSOP20-EP package.

ELECTRICAL SPECIFICATIONS

Parameter

Symbol

Value

Units

Input Voltage

4.5 – 33

V

Output Voltage

VLED

<80

V

LEDs #

4 string

LED Current

120/string

mA

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:

1. Direct PWM Dimming Mode

2. Internal Fixed 23kHz PWM Dimming

Mode

3. Analog Dimming Mode by Input Pulse

4. Internal Analog Dimming Mode

5. Mixed Dimming Mode by Input Pulse

6. Internal Mixed Dimming Mode

• 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,

2V/Step

• 0.15V to 0.5V Latch-Off/Recoverable OCP

Protection Threshold, 50mV/Step

• Recoverable Thermal Shutdown Protection

APPLICATIONS

• Desktop LCD Flat Panel Displays

• All In One

• 2D/3D LCD TVs

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

status, please visit MPS website under Products, Quality Assurance page.

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

Monolithic Power Systems, Inc.