AL8866Q

Description

The AL8866Q is a Buck-Boost, Boost, Buck and SEPIC (single-ended primary-inductance converter) DC-Switching controller designed to drive an external MOSFET for high power automotive LED applications such as automotive front lighting.

The AL8866Q operates within a wide input power supply range from 4.7V to 85V. The AL8866Q bases on a fixed-frequency, peak current-mode control architecture to incorporate spread spectrum frequency modulation technique and achieve Low EMI performance.

The AL8866Q modulates LED current with analog or PWM dimming techniques. Analog dimming response with over 100:1 Linear range is obtained by varying the voltage at the DIM pin. PWM dimming is achieved by directly modulating the same DIM pin with the desired duty cycle.

The AL8866Q integrates soft-start function which limits the current through the inductor and external power switch during initialization start up. It gradually increases the inductor and switch current to minimize potential overvoltage and overcurrent at the output.

The AL8866Q with an open drain fault output indicates protection conditions triggered like LED output overvoltage, LED output open/short, cycle by cycle overcurrent protection, sense resistor and inductor/diode shorted, diode open and thermal shutdown.

The AL8866Q is available in the enhanced thermal SO-8EP package

Feature(s)

• AEC-Q100 (Grade 1)
• Wide Input Voltage Range from 4.7V to 85V
• Pre-Fixed 400kHz Switching Frequency (Factory Set)
• Spread Spectrum Frequency Modulation for Low EMI
• Analog Dimming Range: 1% to 100%
  • 100% Dimming Level ±3% Current Accuracy
  • 20% Dimming Level ±12% Current Accuracy
• PWM Dimming Ratio 100:1 at 200Hz PWM Frequency
• Programmable Soft Start
• Fault Status Indicator for Protections
• Output Overvoltage and LED Open Circuit Protection
• Output Undervoltage and LED Short Circuit Protection
• Cycle-by-Cycle Over Current Limitation Protection
• Sense Resistor Shorted Circuit Protection
• Diode/Inductor Shorted Circuit Protection
• Diode Open Circuit Protection
• Thermal Shutdown
• Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
• Halogen and Antimony Free. “Green” Device (Note 3)
• The AL8866Q is suitable for automotive applications requiring specific change control; this part is AEC-Q100 qualified, PPAP capable, and manufactured in IATF 16949 certified facilities. https://www.diodes.com/quality/product-definitions/

Application(s)

• Automotive front lightings
• Automotive high beams, low beams
• Automotive daytime running lights
• Automotive fog lights, turn lights and position lights
• Other automotive LED lightings