High Power LED Driver with Pre-Emptive Boost for Ultra-High Dimming Ratio and Low Output Ripple

A80602, A80605

Allegro 24-contact QFN ES Package

Description

Top Features

Packaging

The A80602 and A80605 are multi-output LED drivers for automotive applications such as exterior lighting, heads-up display, and mid-size LCD backlighting. They implement a current-mode boost/ SEPIC converter with gate driver for external N-MOSFET. This allows greater output power even at minimum supply voltage.

These devices provide six integrated current sinks driving up to 140 mA per string. Multiple sinks can be paralleled together to achieve higher LED currents up to 840 mA. These ICs operate from single power supply from 4.5 to 40 V; once started, they can continue to operate down to 4 V. This allows them to withstand stop/start, cold crank, and load dump conditions encountered in automotive systems.

The A80602 and A80605 can control LED brightness through external PWM signal. By using the patented Pre-Emptive Boost control, an LED brightness contrast ratio of 15,000:1 can be achieved using PWM dimming at 200 Hz.

The A80605 offers a modified programming range for PEB control, optimized for lower boost switching frequencies (e.g., 400kHz).

  • Automotive AEC-Q100 qualified
  • Enhanced fault handling for ASIL B system compliance
  • Wide input voltage range of 4.5 to 40 V for start/stop, cold crank, and load dump requirements
  • Operate in Boost or SEPIC mode for flexible output
  • Gate driver for external NMOS to deliver higher output power
  • Six integrated LED current sinks, up to 140 mA each
  • Boost switching frequency synced externally or programmed from 200 kHz to 2.3 MHz
  • Programmable boost frequency dithering to reduce EMI
  • Advanced control allows minimum PWM on-time down to 0.3 μs, and avoids MLCC audible noises
  • LED contrast ratio: 15,000:1 at 200 Hz using PWM dimming alone, 150,000:1 when combining PWM and analog dimming
  • Excellent input voltage transient response even at lowest PWM duty cycle
  • Gate driver for optional PMOS input disconnect switch
  • Extensive fault protection features

Typical Applications

24-Pin 4 mm x 4 mm QFN with Wettable Flank

ES Package Documentation

Part Number Specifications and Availability

Documentation and Resources

Documentation

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Technical Article
Pre-Emptive Boost Control Improves LED Driver Performance