Allegro MicroSystems A6282ELP-T

Overview

A6282ELP-T from Allegro MicroSystems is a 16-channel constant-current LED sink driver in a 24-pin TSSOP package with exposed thermal pad, supporting up to 50 mA per channel, 30 MHz serial data rate, and 12 V LED supply voltage. It integrates shift register, latches, and MOS output drivers for direct microprocessor interface in full-color LED display systems.

For engineers reviewing the A6282ELP-T datasheet, A6282ELP-T pinout, A6282ELP-T application, or A6282ELP-T equivalent, key selection criteria include output current accuracy (±3% between channels), Schmitt-trigger noise immunity, Power-On Reset behavior, thermal shutdown at 165°C, and cascading capability via SDO/SDI.

Technical Context

The A6282ELP-T implements a serial-to-parallel CMOS shift register followed by independent output latches, enabling synchronous update of all 16 channels. Its constant-current sink architecture uses an external REXT resistor to set per-channel current with internal 1.21 V reference voltage.

It features integrated undervoltage lockout (UVLO) with 2.5–2.9 V turn-on threshold and thermal shutdown (TSD) at 165°C typical with 15°C hysteresis. All digital inputs include Schmitt triggers, and the OE pin provides active-low output enable with 60 ns propagation delay.

Key Specifications

Pinout & Package

Package: 24-pin TSSOP (LP) with exposed thermal pad, lead-free, 100% matte tin plating. Thermal resistance R_θJA = 28°C/W on 4-layer JEDEC board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC59283DBQR and STP16DP05PTR, the A6282ELP-T uniquely combines 3.0–5.5 V logic compatibility, ±3% channel matching, Schmitt-trigger inputs, and integrated thermal/UVLO protection-making it optimal for outdoor, high-reliability LED display systems where supply stability and thermal margin cannot be assumed.

Availability

A6282ELP-T is available at Aetrix Electronics and suitable for LED signboards, full-color video walls, display backlighting, and multicolor architectural lighting requiring stable component supply across production lifecycles.

Supply support for A6282ELP-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 magnetic sensors and power ICs, headquartered in Worcester, Massachusetts.

The A6282 product line delivers robust, thermally protected constant-current LED drivers optimized for outdoor signage, transportation displays, and industrial lighting where reliability under wide temperature and voltage variation is critical.

FAQ

What is the maximum LED supply voltage supported by the A6282ELP-T?

The A6282ELP-T supports a maximum LED supply voltage (V_LED) of 12 V, as specified in its absolute maximum ratings. This allows driving strings of up to three white LEDs (VF ≈ 3.5–4.0 V each) plus margin for series drop components. Exceeding 12 V risks permanent damage to the output transistors. The device's output regulation degrades above 3 V V_DS, so optimal efficiency requires minimizing V_LED using external Zener or diode drops as described in the A6282ELP-T application notes.

How does the A6282ELP-T set its output current, and what resistor value yields 20 mA per channel?

The A6282ELP-T sets all 16 output currents using a single external resistor (REXT) connected between Pin 23 and GND. With V_EXT = 1.21 V typical, the formula for 4.5–5.5 V V_DD is I_O(max) = (18841.2 / R_EXT) + 0.68. Solving for 20 mA gives R_EXT ≈ 910 Ω. The A6282ELP-T datasheet confirms this value yields 21.4 mA typical at 25°C, within the ±7% inter-IC tolerance band.

Does the A6282ELP-T require external decoupling capacitors, and what values are recommended?

Yes, the A6282ELP-T requires two types of decoupling: a 0.1 μF ceramic capacitor placed as close as possible to the VDD pin (Pin 24) for logic supply filtering, and at least one 10 μF bulk capacitor from the V_LED bus to GND for every two A6282ELP-T devices. These values are specified in the "Application Information" section of the A6282ELP-T datasheet to suppress switching noise and maintain REXT reference stability, especially during high-frequency data transfer.

Can multiple A6282ELP-T devices be cascaded, and what is the maximum clock frequency in cascade mode?

Yes, the A6282ELP-T supports daisy-chaining via its SDO (Pin 22) and SDI (Pin 2) pins. In cascaded configurations, the maximum reliable clock frequency is 25 MHz - lower than the 30 MHz limit for a single device - due to cumulative propagation delays across the chain. The A6282ELP-T functional description explicitly defines f_CLKC = 25 MHz as the cascaded clock rating, and timing diagrams confirm setup/hold margins remain valid at this rate.

What happens to the output latches during a thermal shutdown event on the A6282ELP-T?

During thermal shutdown, the A6282ELP-T disables all 16 output drivers but retains the contents of both the shift register and output latches. The datasheet states: "The shift register and output latches register will remain active during a thermal shutdown event. Therefore, there is no need to reset the data in the output latches." Once junction temperature falls below (T_JTSD – T_JTSDhys) ≈ 150°C, outputs automatically resume operation with the previously latched pattern intact.