Allegro MicroSystems A8519KETTR-R

Overview

A8519KETTR-R from Allegro MicroSystems is an automotive-grade, multi-output LED driver IC designed for LCD backlighting in harsh environments. It integrates a current-mode boost converter with internal 42 V MOSFET and four matched LED current sinks, delivering up to 100 mA per string across four channels, operating from 4.5–40 V input, and supporting up to 44 white LEDs (11 per string) - used in automotive instrument clusters and center-stack displays.

For engineers reviewing the A8519KETTR-R datasheet, A8519KETTR-R pinout, A8519KETTR-R application, or A8519KETTR-R equivalent, key selection criteria include its AEC-Q100 qualification, 0.7% LED current accuracy, 10,000:1 PWM dimming contrast ratio at 100 Hz, programmable 200 kHz–2.15 MHz switching frequency, and integrated fault protection including output short, overvoltage, open/shorted LED detection, and thermal shutdown.

Technical Context

The A8519KETTR-R employs hysteresis-based regulation to maintain stable LED current during ultra-short PWM on-times (<0.5 µs), enabling high-contrast dimming without visible flicker. Its boost converter uses cycle-by-cycle current limiting and supports optional external P-channel MOSFET input disconnect for load-dump fault isolation.

It features synchronized switching (320 kHz–2.3 MHz), dithering to reduce EMI, and dual dimming control via APWM (analog trimming) and PWM pins. The IC performs automatic LED pin detection during startup, rejecting shorted or unused strings using 3.09 kΩ pull-down resistors and voltage thresholds of 70 mV (short), 150 mV (unused), and 325 mV (active).

Key Specifications

Pinout & Package

28-pin 5 × 5 mm QFN with exposed thermal pad (suffix ET); requires ≥8 vias connecting pad to ground plane for thermal reliability in automotive ambient (–40°C to +125°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX20052ATP/V+T and TPS61196RGER, the A8519KETTR-R uniquely combines AEC-Q100 Grade 1 qualification, integrated 42 V boost MOSFET, GATE-driven input disconnect, and hysteresis-based PWM regulation - making it the only option qualified for full-temperature automotive cluster and center-stack deployment with single-chip fault containment.

Availability

A8519KETTR-R is available at Aetrix Electronics and suitable for automotive instrument clusters, center-stack displays, and head-up display subsystems requiring stable component supply across extended temperature and high-reliability production cycles.

Supply support for A8519KETTR-R 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 and magnetic sensors for automotive and industrial applications.

The A8519 product line delivers fault-tolerant, high-efficiency LED drivers optimized for automotive LCD backlighting - emphasizing AEC-Q100 compliance, wide input range, and robust protection against real-world electrical faults like load dump and LED string failure.

FAQ

What is the maximum number of LEDs the A8519KETTR-R can drive, and how are they configured?

The A8519KETTR-R can drive up to 44 white LEDs total - configured as four independent strings of up to 11 LEDs each at 100 mA per string. Each string connects to one of the LED1–LED4 current sink terminals. Strings may be paralleled (e.g., two strings per sink) to achieve up to 400 mA per channel, though this reduces per-string voltage headroom and requires careful thermal design. The 40 V maximum output voltage limits practical string count based on LED forward voltage.

Does the A8519KETTR-R support both PWM and analog dimming, and what contrast ratios are achievable?

Yes, the A8519KETTR-R supports simultaneous PWM and analog (APWM) dimming. Using PWM alone at 100 Hz achieves a 10,000:1 contrast ratio; combining PWM with analog trimming extends this to 100,000:1. This dual-mode capability is implemented via separate APWM and PWM pins, with hysteresis control ensuring stable current regulation even at sub-microsecond PWM on-times - a feature confirmed in the A8519-DS Rev. 11 functional description.

How does the A8519KETTR-R handle fault conditions such as LED string open or short circuits?

The A8519KETTR-R detects open or shorted LED strings during startup and runtime using dedicated voltage thresholds on each LEDx pin (70 mV = short, 150 mV = unused, 325 mV = active). During operation, it continuously monitors for open/shorted diodes, output shorts, overvoltage, and overtemperature. On critical faults like VOUT-to-GND short or overtemperature, the FAULT pin asserts low and the IC either latches off (e.g., input OCP) or auto-retries (e.g., OVP), as specified in the Electrical Characteristics table and Functional Description section of the A8519-DS.

What package type and thermal requirements apply to the A8519KETTR-R?

The A8519KETTR-R uses a 28-pin 5 × 5 mm QFN with exposed thermal pad (suffix ET). Allegro specifies that the exposed pad must be connected to the PCB ground plane using at least eight thermal vias. Thermal resistance is 32°C/W on a JEDEC 4-layer board; derating is required above 125°C ambient. The device's 155°C thermal shutdown threshold and 20°C hysteresis ensure safe operation under sustained load in automotive under-dash environments.

Can the A8519KETTR-R be synchronized to an external clock, and what is the supported frequency range?

Yes, the A8519KETTR-R supports external synchronization via the FSET pin. When driven by an external clock source, it locks to frequencies from 320 kHz to 2.3 MHz - matching its internal programmable range. In synchronized mode, frequency dithering is disabled. This capability enables EMI reduction across multi-converter systems (e.g., display + camera power rails) and is explicitly documented in the Synchronization section of the A8519-DS Rev. 11 datasheet.