Allegro MicroSystems A6213KLJTR-1-T

Overview

A6213KLJTR-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 up to 1.5 A output current (over temperature), supports 6–48 V input, regulates true average LED current via cycle-by-cycle controlled on-time, and drives single-string high-power LEDs in automotive lighting systems including daytime running lights and stop/turn lamps.

For engineers reviewing the A6213KLJTR-1-T datasheet, A6213KLJTR-1-T pinout, A6213KLJTR-1-T application, or A6213KLJTR-1-T equivalent, key selection considerations include its AEC-Q100 qualification, 1.5 A max output current rating (vs. 3 A for A6213), thermal shutdown at 165°C, UVLO threshold of 5.3 V, and compatibility with external PWM dimming at 100 Hz–2 kHz.

Technical Context

The A6213KLJTR-1-T implements fixed on-time, average current mode control using a dedicated CS pin feedback loop with 200 mV regulation threshold. Its internal high-side DMOS switch features 0.25 Ω typical R_DS(on) and cycle-by-cycle current limiting set to 1.9–2.5 A.

Switching frequency is resistor-programmable (via TON pin) from ~500 kHz to 2 MHz; minimum on/off times are 110 ns each. Protection includes undervoltage lockout (5.3 V with 150 mV hysteresis), thermal shutdown (165°C with 25°C hysteresis), and robust fault handling for pin-to-GND shorts, adjacent pin shorts, and open/short external components.

Key Specifications

Pinout & Package

Package: 8-pin narrow SOIC (SOICN) with exposed thermal pad (suffix LJ); RoHS-compliant, lead-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 AL8862Q-7 and LM3409QMY/NOPB, the A6213KLJTR-1-T offers AEC-Q100 qualification, integrated 1.5 A switch with exposed thermal pad, and simplified layout - making it optimal for cost-sensitive, thermally constrained automotive DRL and fog light modules where 1.5 A suffices.

Availability

A6213KLJTR-1-T is available at Aetrix Electronics and suitable for automotive lighting, daytime running lights, and fog lamp applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for A6213KLJTR-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 semiconductor company specializing in high-performance power ICs, magnetic sensors, and motor driver solutions for automotive and industrial markets.

The A6213 product line delivers automotive-grade constant-current LED drivers with integrated power switches, designed specifically for robust, efficient, and compact high-brightness lighting in demanding under-hood and exterior applications.

FAQ

What is the maximum continuous output current rating for the A6213KLJTR-1-T?

The A6213KLJTR-1-T is rated for 1.5 A maximum output current over the full operating ambient temperature range of –40°C to +125°C. This is the guaranteed specification for the A6213-1 variant, distinct from the 3 A rating of the base A6213. The current limit is enforced via internal cycle-by-cycle sensing with a 1.9–2.5 A trip threshold, ensuring safe operation even under transient overload conditions. Designers must verify thermal margin using R_θJA = 35°C/W (4-layer PCB) and derate accordingly at elevated ambient temperatures.

How does the A6213KLJTR-1-T achieve PWM dimming, and what frequency range is supported?

The A6213KLJTR-1-T achieves PWM dimming through direct logic-level control of the EN pin, eliminating need for external dimming circuitry. It supports PWM frequencies from 100 Hz to 2 kHz, with dimming ratios down to 1% achievable (e.g., 50 µs on-time within 5 ms period). The IC maintains immediate LED current response during PWM transitions - no startup delay occurs during normal dimming operation. If EN remains low >17 ms, the device enters ultra-low-power shutdown (1 µA), requiring full restart sequence upon re-enable.

Is the A6213KLJTR-1-T qualified for automotive applications, and what standards does it meet?

Yes, the A6213KLJTR-1-T is AEC-Q100 Grade 1 qualified, meaning it has passed rigorous stress testing for operation from –40°C to +125°C ambient temperature and meets automotive reliability requirements for humidity, vibration, ESD, and latch-up immunity. It is explicitly designed for automotive exterior lighting including DRL, fog lamps, and stop/turn signals. The device also incorporates automotive-grade protections: undervoltage lockout, thermal shutdown with hysteresis, and fault detection for pin shorts, opens, and external component failures - all validated per AEC-Q100 test plans.

What is the function of the TON pin on the A6213KLJTR-1-T, and how is switching frequency set?

The TON pin on the A6213KLJTR-1-T programs the fixed on-time duration, which directly determines switching frequency in this constant-on-time buck controller. A resistor (R_TON) is connected between VIN and TON; typical values range from 63.4 kΩ (1 MHz) to 140 kΩ (500 kHz). The relationship is f_SW ≈ 1 / [0.0139 × (R_TON + 5 kΩ)], where R_TON and R_INT = 5 kΩ are in kΩ and f_SW is in MHz. This resistor-based tuning allows designers to optimize efficiency, EMI, and inductor size without changing IC variants.

Does the A6213KLJTR-1-T require an external output capacitor, and what is the impact of adding one?

The A6213KLJTR-1-T is designed to operate stably without an output filter capacitor - reducing BOM cost and board space. However, a small ceramic capacitor (e.g., 0.68–2.2 µF) may be added across the LED string (LED+ to LED–) to reduce output current ripple. Doing so introduces a slight delay in PWM dimming response and reduces maximum achievable dimming ratio. Capacitors must never be placed between LED+ and GND, as this disrupts CS pin ripple sensing and risks control loop instability. The IC's current regulation remains accurate regardless of output capacitance.