Allegro MicroSystems A8519KLPTR-T-1

Overview

A8519KLPTR-T-1 from Allegro MicroSystems is an automotive-grade, multi-output LED driver IC for LCD backlighting in infotainment and instrument clusters. It integrates a current-mode boost converter (4.5–40 V input, 40 V max output) with four 100 mA LED current sinks, supports PWM + analog dimming for 100,000:1 contrast ratio, and features AEC-Q100 qualification, hysteresis control (150 mV window), and fault protection including OVP, OTP, and LED string diagnostics.

For engineers reviewing the A8519KLPTR-T-1 datasheet, A8519KLPTR-T-1 pinout, A8519KLPTR-T-1 application, or A8519KLPTR-T-1 equivalent, key selection considerations include its 20-pin TSSOP package with exposed thermal pad, 150 mV hysteresis window (distinguishing it from A8519KLPTR-T), 3.9 V minimum operating VIN after startup, cycle-by-cycle overcurrent protection, and integrated gate driver for external P-channel MOSFET input disconnect.

Technical Context

The A8519KLPTR-T-1 implements a fixed-frequency, current-mode boost controller with internal 42 V MOSFET and four matched LED current sinks. Its hysteresis control architecture enables stable regulation at ultra-low PWM on-times (<0.5 µs), critical for high-contrast dimming in automotive displays.

It features dual dimming control: digital PWM input (100–400 Hz) for primary intensity control and APWM pin for analog trimming or secondary dimming. The FSET pin supports programmable switching frequency (200 kHz–2.15 MHz) or synchronization (320 kHz–2.3 MHz), with dithering to reduce EMI.

Key Specifications

Pinout & Package

Package: 20-pin TSSOP with exposed thermal pad (suffix LP); requires ≥8 vias to PCB ground plane for thermal performance (RθJA = 29°C/W on 4-layer JEDEC board).

Key Features

Applications

Equivalent & Alternatives

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

Compared with A8519KLPTR-T, the A8519KLPTR-T-1 delivers superior dimming fidelity at ultra-low duty cycles due to its narrower hysteresis window, while the LM3409QMHX/NOPB offers greater topology flexibility at the cost of increased BOM count, layout complexity, and absence of AEC-Q100 validation.

Availability

A8519KLPTR-T-1 is available at Aetrix Electronics and suitable for automotive infotainment backlighting, instrument cluster illumination, and center stack display applications requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.

Supply support for A8519KLPTR-T-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 semiconductor company specializing in high-performance power ICs and magnetic sensors for automotive and industrial markets.

The A8519 product line is designed specifically for fault-tolerant, high-efficiency LED backlighting in automotive displays, emphasizing load-dump resilience, ultra-high dimming contrast, and integrated protection for safety-critical human-machine interfaces.

FAQ

What distinguishes A8519KLPTR-T-1 from A8519KLPTR-T?

The A8519KLPTR-T-1 uses a 150 mV hysteresis window for improved PWM dimming stability and reduced output voltage ripple, whereas the A8519KLPTR-T uses 350 mV. Both share identical pinout, package (20-pin TSSOP), AEC-Q100 qualification, and electrical specifications except hysteresis. This difference makes A8519KLPTR-T-1 preferable for ultra-high-contrast automotive displays where ripple at low PWM duty cycles must be minimized. The A8519KLPTR-T-1 datasheet explicitly confirms this distinction in the Selection Guide table.

Does A8519KLPTR-T-1 support synchronization with other converters?

Yes, A8519KLPTR-T-1 supports synchronization via its FSET pin, accepting an external clock signal from 320 kHz to 2.3 MHz. When synchronized, dithering is disabled, and the boost switching frequency locks to the external source. The CLKOUT pin provides a buffered copy of the internal oscillator (or synchronized frequency) to drive other converters. This capability is confirmed in the Functional Description and Electrical Characteristics sections of the A8519KLPTR-T-1 datasheet, enabling EMI reduction in multi-rail automotive systems.

How does A8519KLPTR-T-1 protect against VOUT-to-ground short circuits?

A8519KLPTR-T-1 detects VOUT-to-GND shorts using its internal fault block and can drive an external P-channel MOSFET via the GATE pin to disconnect the input supply. This protection requires external components (P-MOSFET, gate resistor) and is detailed in the Typical Application Circuit Showing VOUT-to-Ground Short Protection. The IC monitors VSENSE–VIN differential and triggers GATE shutdown within 3 µs of overcurrent detection. This method avoids reliance on output-side sensing, enabling fast, reliable isolation before damage occurs.

What is the minimum input voltage required for A8519KLPTR-T-1 to operate continuously?

A8519KLPTR-T-1 requires a minimum of 4.5 V at startup to clear UVLO, but once operational, it continues functioning down to 3.9 V - a critical feature for automotive idle-stop systems. This behavior is specified in the Absolute Maximum Ratings and Electrical Characteristics tables, where VUVLOfall is guaranteed at 3.9 V. The 3.9 V operating floor allows uninterrupted backlighting during engine cranking or battery voltage sag, provided the IC has already powered up.

Can unused LED channels on A8519KLPTR-T-1 be left floating?

No, unused LEDx pins on A8519KLPTR-T-1 must be terminated to AGND with a 3.09 kΩ resistor. Floating pins cause undefined behavior during LED pin detection, potentially preventing startup. The datasheet mandates this termination to ensure proper detection (150 mV threshold) and removal from regulation. Failure to terminate unused pins may result in fault latch or failure to enter soft-start. This requirement is explicitly stated in the Pinout Diagrams and Terminal List Table for both LP and ET packages.