Allegro MicroSystems A80603KESJSR

Overview

A80603KESJSR from Allegro MicroSystems is an automotive-grade multi-output LED driver IC integrating a current-mode boost converter with internal 250 mΩ NMOS switch and four precision current sinks. It delivers up to 120 mA per string across four parallel LED channels (480 mA total), operates from 4.5–40 V input, and achieves 15,000:1 PWM dimming contrast ratio at 200 Hz in automotive cluster backlighting applications.

For engineers reviewing the A80603KESJSR datasheet, A80603KESJSR pinout, A80603KESJSR application, or A80603KESJSR equivalent, key selection considerations include its Pre-Emptive Boost control for ultra-low output ripple, programmable 260 kHz–2.3 MHz switching frequency with dithering, 8 ms soft-start timer, AEC-Q100 qualification, and wettable-flank 24-pin QFN package for automated optical inspection.

Technical Context

The A80603KESJSR implements a patented Pre-Emptive Boost (PEB) algorithm that dynamically anticipates LED voltage drops to minimize output capacitor ripple and eliminate MLCC audible noise. Its boost converter supports both Boost and SEPIC topologies, with internal NMOS switch (250 mΩ typ.), programmable frequency via FSET resistor or external sync, and Clock-Out pin enabling synchronized dithering across multiple converters-even when LEDs are off.

Fault protection includes open/short detection on all four LED pins, overvoltage (OVP) and undervoltage (UVP) monitoring, thermal shutdown (170°C), input overcurrent handling with optional P-channel disconnect FET control via GATE pin, and auto-recovery from LED short-to-GND faults. The FAULT pin is open-drain and asserts low on detected faults.

Key Specifications

Pinout & Package

Package: 24-pin 4 mm × 4 mm QFN with wettable flank, exposed thermal pad, and 100% matte tin plating. Requires ≥8 vias connecting the exposed pad directly to PCB ground plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LED driver applications.

Compared with AL8862T-7DT and TPS92692QPWPRQ1, the A80603KESJSR uniquely combines four-channel current sinking, Pre-Emptive Boost ripple suppression, programmable dithering with CLKOUT synchronization, and AEC-Q100 Grade 1 qualification - making it the only option for high-reliability, high-contrast, multi-string automotive backlighting where acoustic noise and EMI are critical.

Availability

A80603KESJSR is available at Aetrix Electronics and suitable for automotive instrument clusters, infotainment displays, and exterior lighting systems requiring stable component supply, AEC-Q100 compliance, and production-ready thermal performance.

Supply support for A80603KESJSR 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 semiconductor company specializing in high-performance power ICs, magnetic sensors, and motor driver solutions for automotive and industrial markets.

The A80603KESJSR belongs to Allegro's automotive LED driver product line, designed specifically for high-dynamic-range, low-noise backlighting in safety-critical vehicle displays - emphasizing ASIL-B readiness, transient resilience, and EMI-controlled switching.

FAQ

What is the soft-start time of the A80603KESJSR?

The A80603KESJSR has a fixed 8 ms soft-start ramp time, as specified in the Selection Guide for this exact part number. This value is distinct from the 16 ms soft-start of the A80603KESJSR-1 variant. The 8 ms duration limits inrush current and ensures consistent startup behavior regardless of PWM dimming duty cycle, supporting reliable operation in automotive stop/start cycles.

Does the A80603KESJSR support both Boost and SEPIC topologies?

Yes, the A80603KESJSR supports both Boost and SEPIC configurations, as confirmed in the Features section and Functional Block Diagram. Topology selection is determined by external component placement - specifically the connection of the SW pin, inductor, and diode/capacitor. SEPIC mode extends operational flexibility for applications where output voltage may exceed or fall below input voltage, such as in 12 V automotive systems driving high-V_F LED strings.

How does the Pre-Emptive Boost (PEB) feature improve performance in the A80603KESJSR?

The Pre-Emptive Boost (PEB) feature in the A80603KESJSR dynamically anticipates LED forward voltage drops before they occur, adjusting the boost converter duty cycle proactively. This minimizes output voltage ripple to <10 mV_PP, eliminating audible noise from MLCCs and enabling use of smaller, lower-ESR output capacitors. It directly enables the 15,000:1 PWM dimming contrast ratio at 200 Hz without compromising regulation stability.

Can the A80603KESJSR drive more than 120 mA per LED string?

No - the A80603KESJSR is rated for up to 120 mA per individual LED string (LED1–LED4). However, its four current sinks can be paralleled externally to deliver up to 480 mA total current, as stated in the device description. This requires routing all four LEDx pins to a common cathode node and ensuring thermal derating per the R_θJA = 37 °C/W specification. Individual channel accuracy remains ±0.7% even in paralleled configuration.

What fault conditions cause the FAULT pin to assert on the A80603KESJSR?

The FAULT pin on the A80603KESJSR asserts low for LED pin short-to-GND, open LED strings, FSET or ISET pin shorts/opens, overtemperature (>170°C), overvoltage (OVP trip), undervoltage (UVP trip), and boost switch overcurrent. It does not assert for input UVLO or EN deactivation. The FAULT pin is open-drain and requires an external 10 kΩ pull-up resistor to the system logic rail, as specified in the Terminal List Table.