ALT80600 4-Channel LED Driver

Allegro MicroSystems' ALT80600 is an LED driver for precise control of dimming ratio and elimination of audible noise

Image of ALT80600 4-Channel LED driverAllegro MicroSystems' ALT80600 is a 4-channel LED driver capable of up to 120 mA with total LED current capability of 480 mA. It is designed with an innovative and patented pre-emptive boost (PEB) control which substantially reduces output voltage ripple and eliminates the common problem of audible noise during PWM from ceramic output capacitors, while also requiring less output capacitance overall. LED brightness contrast ratio of 15,000:1 can be achieved using PWM-only dimming at 200 Hz, across the full range of operation. A higher ratio of 150,000:1 is also possible when using a combination of PWM and analog dimming.

The ALT80600 can be powered directly from a vehicle battery, and features operating input voltage from 4.5 V to 40 V. Once started, it can continue to operate down to 3.9 V. This allows the device to withstand stop/start, cold crank, double battery, and load dump conditions encountered in automotive systems. The device combines a switching converter with integrated MOSFET and four current sinks and can be configured in a boost or SEPIC topology to cover a wide range of application configurations. The switching converter is designed for low EMI, including programmable switching frequency, controlled switching slew rate, and programmable dithering. It also features a clock-out (CLKOUT) pin to allow other switching converters to be synchronized to ALT80600's switching frequency for enhanced EMI performance of the overall system. The ALT80600 is a robust device with a host of safety and protection features required for automotive applications. The device is available in 4x4 QFN-24 wettable flank with exposed thermal pad (ES suffix), a smaller package than direct competition.

The ALT80600 is the first product released in Allegro's Gen 4 LED backlight devices line. It uses Allegro's patented pre-emptive boost IP for more precise control of dimming ratio and elimination of audible noise due to capacitor singing. For even higher output power, the ALT80601/02 (with external boost FET) is currently in development.

Features and Benefits
  • Best-in-class, ultra-wide true PWM dimming ratio
    • 15,000:1 PWM-only dimming ratio @ 200 Hz
    • 150,000:1 combined PWM / ADIM ratio
  • No audible noise using MLCC
  • Requires less output capacitance than the competition
  • Small yet thermally efficient 4 mm x 4 mm wettable flank eQFN
  • Low EMI solution
    • Extremely low VOUT ripple
    • Programmable dithering capability
  • Wide input voltage operation
    • As low as 3.9 V (UVLO) for idle-stop compliance
Automotive Applications
  • LCD backlighting
  • Instrument clusters
  • Heads-up displays
  • Exterior lighting

ALT80600 4-Channel LED Driver

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Published: 2018-08-22