Diodes Incorporated AL5816QEV1

Overview

AL5816QEV1 from Diodes Incorporated is an evaluation board for the AL5816 adjustable linear LED driver IC, designed to demonstrate constant-current control of medium-to-high-power LED strings using external NPN transistor Q1 (FZT651TA) and a 0.4Ω sense resistor. It supports 4.5–60VDC input, delivers up to 1A LED current across 1–17 LEDs, and enables PWM dimming >200Hz with <3% current regulation tolerance over temperature.

For engineers reviewing the AL5816QEV1 datasheet, AL5816QEV1 pinout, AL5816QEV1 application, or AL5816QEV1 equivalent, this board provides validated reference design implementation, thermal performance validation under real load conditions, and direct verification of FB voltage regulation at 0.2V, PWM response fidelity, and UVLO/thermal shutdown behavior.

Technical Context

The AL5816QEV1 implements a linear constant-current architecture where the AL5816 IC regulates LED current via feedback at its FB pin held precisely at 0.2V across R3 (0.4Ω), enabling 1A output. Input voltage range (4.5–60VDC) and dropout headroom are maintained by driving the base of Q1 (SOT223 NPN) with up to 15mA sourced from the AL5816's internal driver.

PWM dimming operates by applying logic-level signals (>200Hz) to the dedicated PWM pin, directly modulating the AL5816's internal current sink without affecting FB regulation accuracy. Under-voltage lockout activates below ~4.2V, and thermal shutdown engages above 150°C junction temperature-both verified on this board layout with copper pour and thermal vias.

Key Specifications

Availability

AL5816QEV1 is available at Aetrix Electronics and suitable for commercial lighting prototyping, industrial LED driver qualification, and appliance backlight validation requiring stable component supply and traceable reference design implementation.

Supply support for AL5816QEV1 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 semiconductor manufacturer specializing in discrete, analog, and mixed-signal solutions for power management, signal integrity, and lighting applications.

The AL5816 product line targets high-efficiency, thermally robust linear LED drivers for cost-sensitive, space-constrained lighting systems where precision current regulation and wide input range outweigh switching noise concerns.

FAQ

What is the maximum number of LEDs supported on AL5816QEV1?

The board supports up to 17 LEDs in series when powered at 60V input, assuming typical forward voltage of 3.2V per white LED. At lower input voltages, the count reduces proportionally to maintain sufficient headroom for Q1 saturation and AL5816 FB regulation stability.

Can AL5816QEV1 be used with MOSFETs instead of the onboard NPN transistor?

Yes-the AL5816 IC is designed to drive either bipolar transistors or N-channel MOSFETs. To use a MOSFET, replace Q1 (FZT651TA) with a logic-level N-channel device and adjust gate drive routing; the board's footprint and thermal layout accommodate such substitution with minor rework.

How is LED current adjusted on AL5816QEV1?

LED current is set by the 0.4Ω sense resistor (R3) between FB and GND, yielding 1A at the nominal 0.2V FB reference. For other currents, replace R3 with R = 0.2V / I_LED; e.g., 0.2Ω for 1A, 0.1Ω for 2A (subject to thermal limits of R3 package and PCB copper).

Does AL5816QEV1 include protection features beyond thermal shutdown?

Yes-it implements input under-voltage lockout (UVLO) that disables output below ~4.2V, preventing erratic startup or brown-out operation. No overvoltage or reverse-polarity protection is integrated; external TVS diodes or polarity protection must be added in end-equipment designs.