Allegro MicroSystems A6217KLJTR-1-T

Overview

A6217KLJTR-1-T from Allegro MicroSystems is an automotive-grade, constant-current PWM-dimmable buck LED driver IC with integrated high-side N-channel DMOS switch. It delivers 1.5 A true average output current across 6–48 V input, supports up to 2.2 MHz switching (dithered ±5%), and regulates LED string voltage automatically for optimal efficiency in single-string configurations. Used in daytime running lights and rear fog lamps.

For engineers reviewing the A6217KLJTR-1-T datasheet, A6217KLJTR-1-T pinout, A6217KLJTR-1-T application, or A6217KLJTR-1-T equivalent, key selection criteria include its AEC-Q100 qualification, 1.5 A max output current at full temperature range, SOICN-8 wettable flank package with exposed thermal pad, and direct logic-level PWM dimming via EN pin (100 Hz–2 kHz).

Technical Context

The A6217KLJTR-1-T employs fixed on-time, average current mode control with cycle-by-cycle current limiting. Its internal 5.3 V linear regulator powers gate drive circuitry, while dithered oscillator (±5% range, ~11 kHz modulation) reduces EMI peaks.

It integrates UVLO (5.3 V threshold, 150 mV hysteresis), thermal shutdown (165 °C, 25 °C hysteresis), and robust fault protection-including adjacent pin shorts, pin-to-GND shorts, and open/short detection on CS and SW nodes.

Key Specifications

Pinout & Package

Package: 8-pin narrow SOIC (SOICN-8) with wettable flank leads and exposed thermal pad (suffix LJ); Pb-free, 100% matte-tin leadframe plating.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar constant-current buck LED driver applications.

Compared with AL8862SP-13 and LM3409QMY/NOPB, the A6217KLJTR-1-T uniquely combines AEC-Q100 qualification, integrated 1.5 A switch, and ±5% dithering in a thermally enhanced SOICN-8 package-enabling drop-in automotive LED lighting designs with minimal external components and proven EMC performance.

Availability

A6217KLJTR-1-T is available at Aetrix Electronics and suitable for automotive lighting, daytime running lights, and rear fog lamps requiring stable component supply with AEC-Q100 assurance and long-term production continuity.

Supply support for A6217KLJTR-1-T 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, founded in 1989 and headquartered in Manchester, NH.

The A6217 product line delivers automotive-grade constant-current LED drivers optimized for safety-critical exterior lighting, emphasizing thermal robustness, EMI resilience, and functional safety-ready protection features.

FAQ

What is the maximum continuous output current of the A6217KLJTR-1-T?

The A6217KLJTR-1-T is rated for 1.5 A maximum true average output current across its full operating junction temperature range of –40°C to +125°C. This is confirmed in the Selection Guide and Electrical Characteristics table, where the A6217-1 variant specifies ISWLIM min/typ/max values of 1.9/2.2/2.7 A, supporting 1.5 A continuous operation with margin. The A6217KLJTR-1-T part number explicitly maps to the "A6217-1" variant per Allegro's packaging and current rating documentation.

Does the A6217KLJTR-1-T require an external MOSFET?

No, the A6217KLJTR-1-T integrates a high-side N-channel DMOS switch with R_DS(on) = 0.25 Ω typical, eliminating the need for an external MOSFET. This is stated in the DESCRIPTION section ("integrates a high-side N-channel DMOS switch") and confirmed in the ELECTRICAL CHARACTERISTICS table under "Buck Switch On-Resistance." The functional block diagram also shows the internal "Buck Switch" and "IC and Driver" blocks feeding directly to the SW pin.

What package type does the A6217KLJTR-1-T use, and is it RoHS compliant?

The A6217KLJTR-1-T uses the 8-pin narrow SOIC (SOICN-8) package with wettable flank leads and an exposed thermal pad (suffix LJ). It is lead (Pb) free and features 100% matte-tin leadframe plating, satisfying RoHS Directive 2011/65/EU requirements. This is documented in the PACKAGE section and confirmed in the Selection Guide, which lists "8-pin SOICN with exposed thermal pad" for A6217KLJTR-1-T.

How is PWM dimming implemented on the A6217KLJTR-1-T?

PWM dimming on the A6217KLJTR-1-T is implemented directly via the EN pin, which accepts logic-level signals from 100 Hz to 2 kHz. The IC interprets the duty cycle of this signal to proportionally control LED brightness, with no external components required. The Functional Description confirms EN is "high-voltage tolerant" and "logic-level compatible," and Figure 2 demonstrates clean PWM waveforms at 200 Hz with 50% and 2% duty cycles.

Is the A6217KLJTR-1-T qualified to AEC-Q100, and what grade does it meet?

Yes, the A6217KLJTR-1-T is AEC-Q100 qualified and meets Grade 1 requirements (operating ambient temperature range –40°C to +125°C). This is explicitly listed under "FEATURES AND BENEFITS" and reinforced in the Selection Guide and Functional Description sections. The device's thermal shutdown threshold (165°C) and hysteresis (25°C), along with R_θJA = 35 °C/W, support reliable operation within Grade 1 ambient limits.