ALT80802: Wide Input Voltage, Adjustable Frequency, Buck-Boost or Buck 2 Amp LED Driver

Description

The ALT80802 is a high-frequency switching regulator that provides constant output current to drive high-power LEDs. It integrates a power MOSFET for step-down or inverting buck boost conversion. The wide input range of 3.8 to 50 V makes the ALT80802 suitable for a wide range of lighting applications, including those in an automotive input environment. The device rating also enables a simple solution for driving 3 to 4 WLEDs in buck boost configuration—a very common application requirement for automotive lighting applications.

The ALT80802 is designed to aid in EMC/EMI design by frequency dithering, soft freewheel diode turn-off, and well controlled switch node slew rates. A programmable oscillator allows the ALT80802 to switch outside EMI-sensitive frequency bands such as the AM band.

With current-mode control and simple external compensation, the ALT80802 can achieve fast transient response. The control loop of the ALT80802 is designed for PWM dimming operation to achieve low dimming on-time and low turn-on overshoot. In buck-boost operation, the ALT80802 reduces the current overshoot normally caused by right half plane zero effect during a PWM diming turn-off transient. Extensive protection features of the ALT80802 include pulse-by pulse current limit, hiccup mode short-circuit protection, open/ short freewheeling diode protection, BOOT open/short voltage protection, VIN under voltage lockout, and thermal shutdown. Also, it includes internal clamp to prevent output voltage runaway if output LED string is opened in buck-boost operation.

The ALT80802 is available in a small 10 pin DFN package with thermal pad and wettable flank (automotive qualified).

 

Top Features

  • AEC-Q100 qualified—Automotive-Grade; Facilitates system level certification
  • Simple operation—Same PN can be in buck-boost or buck mode
  • Supply voltage from 3.8 to 50 V
  • Handles automotive load dump and cold crank
  • Can be run in buck mode from a pre-boost supply
  • Supports up to 16 V output in buck-boost mode
  • Addresses automotive market need for 3-4 WLED solution
  • 150 mΩ integrated MOSFET switch
  • Supports up to ~2A in buck mode and ~750mA in buck-boost (Vinmin dependent)
  • Programmable switching frequency up to 2.5 MHz, with frequency dithering
  • Designed for low EMC
  • Operation can be above AM band
  • Small solution size
  • Integrated level shifting
  • Allows ground-referenced enable and fault flag in buck-boost mode
  • PWM dimming via direct logic input or power supply voltage
  • Supports all automotive PWM techniques including “single-wire”
  • Extensive protection and fault table
  • Robust, does not require extra protection components
  •  3x3mm DFN-10 wettable flank exposed pad package
  • Small yet thermally efficient
  • Wettable flank eliminates need for x-ray inspection

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Compliant
Part Composition /
RoHS Data
Comments Samples Check Stock
APEK80802KEJ-01-MH-BB DEMO BOARD -20°C to 85°C No -- Contact your
local sales rep
Check
Distributor Stock
ALT80802KEJJTR 10-lead DFN -40°C to 125°C Yes View Data Contact your
local sales rep
Check
Distributor Stock

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