Allegro MicroSystems A80804KETASR-1

Overview

A80804KETASR-1 from Allegro MicroSystems is a high-power automotive LED driver IC implementing a current-mode boost/SEPIC converter with external N-channel MOSFET gate driver and four integrated 210 mA LED current sinks. It supports 4.5–40 V input, achieves 15,000:1 PWM dimming contrast at 200 Hz, and is AEC-Q100 qualified for exterior lighting and HUD applications.

For engineers reviewing the A80804KETASR-1 datasheet, A80804KETASR-1 pinout, A80804KETASR-1 application, or A80804KETASR-1 equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, fault-handling behavior, and direct alternative part comparisons - all grounded in Allegro's official A80601 family documentation and package mapping.

Technical Context

The A80804KETASR-1 implements Pre-Emptive Boost (PEB) control to minimize output ripple and enable ultra-high dimming ratios without MLCC audible noise. Its gate driver supports external N-MOSFET switching at programmable frequencies from 260 kHz to 2.3 MHz, with dithering for EMI reduction and CLKOUT synchronization capability.

It features dual fault-handling modes: 'One-Out-All-Out' (as specified for A80601-1 variants), cycle-by-cycle current limiting, overvoltage protection via OVP pin, thermal shutdown at 170°C, and LED string short/open detection during startup. The ISET pin sets LED current with ±0.7% accuracy, and ADIM supports analog dimming with 1.5–98.5% duty cycle range.

Key Specifications

Pinout & Package

24-pin 4 mm × 4 mm QFN with wettable flank and exposed thermal pad - optimized for automotive thermal cycling reliability and automated optical inspection (AOI).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-power automotive LED driver applications.

Compared with A80601KESJSR-1, A80804KETASR-1 offers better thermal performance (lower RθJA) in the ET package, while MAX20052ATP/V+T trades external drive flexibility and dimming fidelity for integration - making A80804KETASR-1 optimal for high-reliability, high-fidelity automotive lighting where thermal margin and acoustic silence are non-negotiable.

Availability

A80804KETASR-1 is available at Aetrix Electronics and suitable for automotive exterior lighting, heads-up display backlighting, and mid-size LCD instrument clusters requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant sourcing.

Supply support for A80804KETASR-1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Allegro MicroSystems is a U.S.-based designer and manufacturer of high-performance power ICs and magnetic sensors, serving automotive, industrial, and consumer markets since 1989.

The A80804KETASR-1 belongs to Allegro's A80601 family of high-power LED drivers engineered specifically for ASIL B-compliant automotive lighting systems demanding ultra-high dimming ratios, robust fault handling, and thermal resilience in harsh environments.

FAQ

What is the key difference between A80804KETASR-1 and A80601KESJSR-1?

The A80804KETASR-1 and A80601KESJSR-1 share identical die functionality and One-Out-All-Out fault handling, but differ in package: A80804KETASR-1 uses the ET package (4 mm × 4 mm QFN with wettable flank), offering lower thermal resistance (RθJA = 34°C/W) than the ES package (37°C/W) used by A80601KESJSR-1. This makes A80804KETASR-1 preferable for thermally constrained layouts. Both are pin-compatible and electrically identical.

Does A80804KETASR-1 support both PWM and analog dimming simultaneously?

Yes, A80804KETASR-1 supports combined PWM and analog dimming to achieve up to 150,000:1 contrast ratio. The ADIM pin accepts either a DC voltage (0.2–2.0 V) for analog control or a 40–1000 kHz PWM clock for APWM mode. When both are active - e.g., coarse analog adjustment plus fine PWM modulation - the A80804KETASR-1 internally blends them to extend effective dimming resolution beyond what either method achieves alone.

What fault conditions trigger the FAULT pin on A80804KETASR-1?

The FAULT pin on A80804KETASR-1 is pulled low for overtemperature (TJ ≥ 170°C), output overvoltage (OVP trip), LED string short-to-GND or open-circuit, FSET/ISET pin shorts, input overcurrent (via VSENSE), and boost switch overcurrent. In One-Out-All-Out mode, any single fault causes immediate latched shutdown - the FAULT pin remains low until cleared by EN low >16 ms or VIN UVLO reset. No external pull-down is needed; a 10 kΩ pull-up to 3.3 V or 5 V is standard.

Can A80804KETASR-1 drive LED strings with different forward voltages?

Yes, A80804KETASR-1 supports independent LED strings with varying forward voltages because each LEDx pin operates as a separate current sink with its own regulation loop. The boost converter output adjusts dynamically to meet the highest Vf string requirement, while lower-Vf strings remain in regulation. However, all strings must share the same anode connection to VOUT, and unused LEDx pins must be terminated to AGND with 2.37 kΩ resistors to prevent false fault detection during startup.

Is external synchronization supported on A80804KETASR-1, and how is it implemented?

Yes, A80804KETASR-1 supports external synchronization via the FSET pin. Applying a clean square-wave clock (260 kHz–2.3 MHz) to FSET overrides the internal oscillator and locks the switching frequency - including dithering modulation if enabled - to the external source. This allows precise timing alignment with other converters in multi-rail systems. During sync loss, the device reverts to internal frequency after a 150 ns minimum off-time detection window, ensuring graceful fallback without latch-up.