Diodes Incorporated AL8843QEV1

Overview

AL8843QEV1 from Diodes Incorporated is an evaluation board for the AL8843Q hysteresis-mode DC-DC step-down LED driver IC, designed to drive 1–10 series-connected LEDs at up to 2A output current from 5–40V input. It integrates the AL8843QSP-13 in SO-8EP package, a 40V NDMOS switch, and supports PWM/analog dimming via the CTRL pin. The board delivers up to 60W output power and features inherent open-circuit and short-circuit LED protection.

For engineers reviewing the AL8843QEV1 datasheet, AL8843QEV1 pinout, AL8843QEV1 application, or AL8843QEV1 equivalent, this board enables rapid validation of LED current accuracy (±4%), soft-start behavior (adjustable via C4), thermal performance under 60W load, and dimming interface compatibility with automotive lighting control systems.

Technical Context

The AL8843QEV1 implements a fixed-frequency hysteresis-controlled buck converter topology optimized for constant-current LED driving. It uses high-side current sensing with an external sense resistor (R1/R2 = 0.1Ω) to regulate average LED current at 2A, and relies on the AL8843Q's internal 40V NDMOS switch operating up to 1MHz switching frequency.

Dimming is implemented through a single CTRL pin accepting either 0.4–2.5V analog signals (10–100% I_LED) or 100Hz–1kHz PWM (1–100% duty cycle). Shutdown occurs when CTRL voltage drops ≤0.3V. Protection includes OTP, LED open-circuit detection, and LED short-circuit limiting.

Key Specifications

Availability

AL8843QEV1 is available at Aetrix Electronics and suitable for automotive daytime running lights, front/rear fog lights, and turn/stop light development requiring stable component supply and fast-turn evaluation capability.

Supply support for AL8843QEV1 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in power management, signal integrity, and lighting solutions for automotive and industrial markets.

The AL8843Q product line targets high-reliability, constant-current LED drivers for automotive exterior lighting, emphasizing integrated protection, wide input range, and single-pin dimming simplicity.

FAQ

What is the default LED current setting on AL8843QEV1?

The board is factory preset to 2A LED current using parallel 0.1Ω resistors R1 and R2. This configuration matches the typical requirement for high-intensity automotive LED strings and can be recalibrated by modifying the sense resistance network per AL8843Q's current-sense equation (I_LED ≈ 0.2V / R_SENSE).

How do I enable PWM dimming on AL8843QEV1?

To enable PWM dimming, remove capacitor C4 and apply a PWM signal (low level <0.3V, high level >2.5V) between CTRL and GND. Recommended frequency is 100Hz–1kHz with 1–100% duty cycle. The AL8843Q internally synchronizes LED current modulation to the applied PWM edge, ensuring flicker-free dimming down to 1% brightness.

Does AL8843QEV1 support analog dimming, and what is the control voltage range?

Yes - analog dimming is supported by installing a 470nF capacitor at C4 and applying a DC voltage of 0.4V–2.5V to CTRL relative to GND. This linearly scales output current from 10% to 100% of nominal I_LED, providing smooth, low-noise brightness control ideal for interior lighting applications.

What protections are implemented on AL8843QEV1, and how are they verified?

The board demonstrates three key protections: LED open-circuit (detected via missing current ramp at SW node), LED short-circuit (limited by internal current foldback), and over-temperature (OTP shutdown confirmed in thermal test figures). These are validated in the User Guide's functional waveforms (Pages 7–8) using oscilloscope captures under fault conditions.