8-String 60mA LED Drivers with Integrated Boost Controller and Phase Shifted Dimming
• Up to 8 parallel 60mA LED strings with up to 10 series white LEDs per string
• Integrated boost controller (MSL3086/88)
• Offers true 4095:1 (12-bit) LED dimming at 120Hz
• String open circuit and LED short circuit fault detection and automatic correction
• ±3% current accuracy and current balance
• Single resistor sets current for all LED strings
• Simple to use external PWM dimming
• Optional internal PWM dimming
• Automatic string phasing reduces EMI and supply ripple
• Synchronizes PWM dimming to LCD panel refresh rate
• Frequency multiplier allows PWM dimming at multiples of LCD panel refresh frequency (see Programming Guide)
• 1MHz l2C/SMBus interface; use optional
• Resistor programmable LED short circuit threshold
• Die over-temperature cut-off protection
• -40°C to +855C operating temperature range
• Lead free, halogen free, RoHS compliant package
The MSL3086/88 8-channel LED drivers with integrated boost regulator controller offer a complete solution to drive up to eight parallel LED strings at up to 40V. The LED current sinks control up to 60mA peak for up to 19W of LED power. A single resistor sets LED current with string matching and accuracy within ±3%.
The advanced integrated PWM circuitry allows up to 4095:1 dimming, and offers simple PWM dimming control. The MSL3086 uses a single PWM input to control the LED dimming signals. The MSL3088 has two inputs, one for frequency and the other for duty cycle. Additionally, internal registers, available through the l2C interface, optionally control PWM dimming frequency and/or duty cycle.
The MSL3086/88 feature phase-shifted PWM dimming to reduce the boost regulator transient response. The integrated fault detection circuitry detects and acts upon string open-circuit and LED short circuit faults, boost regulator over-voltage faults, and die over-temperature faults.
A proprietary Efficiency Optimizer maintains sufficient boost regulator output voltage for proper LED current while minimizing power use. A 1MHz l2C/SMBus serial interface allows optional dimming control, fault inspection and control of device parameters; for serial interface information see the MSL3040/50/60/80/86/87/88/89 Programming Guide.
The MSL3086/88 are offered in the 24-pin VQFN lead-free, halogen-free, RoHS compliant package and operate over -40°Cto+85eC.