A80601 and A80604: High Power LED Driver with Pre-Emptive Boost for Ultra-High Dimming Ratio and Low Output Ripple

The A80601 and A80604 are multi-output LED drivers for automotive applications that 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 four integrated current sinks driving up to 210 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, it can continue to operate down to 4 V. This allows it to withstand stop/start, cold crank, and load dump conditions encountered in automotive systems.

The A80601 and A80604 can control LED brightness through external PWM signal. By using the patented Pre-Emptive Boost (PEB) control, an LED brightness contrast ratio of 15,000:1 can be achieved using PWM dimming at 200 Hz.

The A80604 offers a modified programming range for PEB control, optimized for lower boost switching frequencies (e.g., 400kHz).

Both devices provide protection against output short, overvoltage, open- or shorted-LED pin, and overtemperature. A cycle-by-cycle current limit protects the external boost switch against high current overloads. An external P-MOSFET can optionally be used to disconnect input supply in case of output to ground short fault. The A80601-1/A80604-1 are similar to A80601/A80604 except they adopt ‘One-Out-All-Out’ fault handling.

Featured Applications include:

• Automotive infotainment backlighting
• Instrument Cluster
• Automotive heads-up display
• Automotive interior and exterior lighting

• 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
• Four integrated LED current sinks, up to 210 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