MP4657B 4-16V, 5kHz Single-Stage Flyback SOIC

MP4657B 4-16V, 5kHz Single-Stage Flyback SOIC

The MP4657B is a single-stage flyback, 4-string LED driver and system voltage controller for LED backlighting on the secondary side.

Key Specifications

Features

• Single-Stage Flyback for High-Efficiency LED Current and System Voltage Regulation
• Individual Control Method for the LED Driver Stage and System Voltage Stage
• 4V to 16V Supply Voltage
• 4-String, 80V LED Current Balancing
• 1.5% System Voltage Accuracy
• 1.5% LED Current Accuracy and 2% LED Current Balancing
• High-Efficiency, Low LEDx Regulation Voltage
• Fast Dynamic Control, Fast Response
• System Supply Over-Voltage Protection (OVP)
• System Supply Short Protection

Typical Application Circuit

Applications

• LCD Monitors and TVs
• Desktop LCD Flat-Panel Displays

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