A8500EECTR-T

• Product introduction

A8500is a multi-output WLED for mid-size display backlightingdrive。 The A8500 integrates a boost converter and eight sink currents to provide a flexible WLED/RGB backlight driver. The boost converter provides output voltages up to V. Flexible channel selection control and high voltage capacity for a variety of LED backlight applications. The A8500 can support any application requiring 4 to 96 WLEDs. The boost converter is a constant frequency current mode converter.

Each LED channel can sink 25 mA, and for higher currents, the channels can be connected in parallel. Flexible light and dark control allows the output channels to operate at adjustable DC values or as an externally controlled PWM duty cycle.

The A8500 is available in 26-pin, 4 mm × 4 mm QFN/MLP packages with a nominal height of only 0.75 mm. Applications include:

• Thin notebook display
• LCD TV
• RGB backlight
• GPS system
• Portable DVD player
• • Active current sharing between ±1.5% typical current matched LED string and ±1.2% typical accuracy
  • Drive up to 12 serial × 8 parallel = 96 LEDs (V_f = 3.2 V, I_f = 20 mA)
  • Flexible shading control using alternative methods:
    • LED duty cycle (PWM pin)
    • DC current using serial programming (EN pin)
    • DC current using external PWM signal (APWM pin)
    • External resistors
  • Boost converter with integrated 50 V, 2 A DMOS
  • The LED sink current rating is 25 mA
  • 200 kHz to 2 MHz switching frequency
  • Turn on the LED to disconnect
  • Boost current limit, thermal shutdown, and soft-start
  • There is no audible ceramic capacitor noise during PWM dimming control
  • Adjustable Overvoltage Protection (OVP)
  • LED modules using ESD capacitors do not require pull-up resistors