MP3398H 4.5-33V Step-Up WLED Controller SOIC

MP3398H 4.5-33V Step-Up WLED Controller SOIC

The MP3398H is a step-up controller with four LED current channels, designed to drive WLED arrays for large LCD panel backlighting applications.

Key Specifications

Features

• 4-String, Max 400mA/String WLED Driver
• 4.5V to 33V Input Voltage (VIN) Range
• 80V Absolute Maximum Rating for Each String
• 1.5% Current Matching Accuracy between Each String
• Direct Pulse-Width Modulation (PWM) Dimming Mode
• Analog Dimming Mode via PWM Input or DC Input
• Cascading Capability with a Single Power Source
• LED Open and Short Protection
• Configurable, Recoverable Over-Voltage Protection (OVP)
• 540mV Cycle-by-Cycle Current Limit

Typical Application Circuit

Applications

• Desktop LCD Flat-Panel Displays
• All-in-One PCs

Design Notes

• Channel-to-channel current matching sets backlight uniformity; check the matching spec at the current you will actually run.
• In boost topologies the OVP threshold must clear the worst-case forward voltage of the longest string, including temperature and binning spread.
• Keep PWM dimming above 200 Hz to stay clear of visible flicker, and away from the audio band if the product has a speaker.
• Size the inductor and output capacitor for the string current ripple, not the total LED current.

Common Questions