Diodes Incorporated AL5890-20Y-13

Overview

AL5890-20Y-13 from Diodes Incorporated is a 20mA fixed-output, high-voltage linear constant current LED driver in SOT89 package, supporting up to 400V DC input voltage and operating across −40°C to +105°C ambient. It functions as a two-terminal series regulator for high-side or low-side LED chain control, with ±2.0mA (typ.) current accuracy, thermal foldback protection at +130°C junction, and 7V minimum turn-on voltage. Used in commercial downlights and architectural lighting where compact, resistorless current regulation is required.

For engineers reviewing the AL5890-20Y-13 datasheet, AL5890-20Y-13 pinout, AL5890-20Y-13 application, or AL5890-20Y-13 equivalent, this page delivers verified technical context, real-world design meaning of specifications, validated pin functions, confirmed alternative parts with functional differences, and supply-ready availability details - all grounded in Diodes' DS40280 Rev. 3 documentation.

Technical Context

The AL5890-20Y-13 implements a bandgap-referenced linear current regulator with internal voltage reference and feedback loop, enabling stable 20mA output without external resistors. Its architecture supports bidirectional placement (IN-to-OUT current flow) and operates with no gate drive or switching elements - purely analog regulation.

Thermal foldback activates at +130°C junction temperature, linearly reducing output current to limit power dissipation; startup occurs when VIN–OUT exceeds 7V, and line regulation remains within ±1.5% over 20–60V input range. The device tolerates up to 425V absolute maximum input-to-output differential.

Key Specifications

Pinout & Package

SOT89 package: thermally enhanced 3-pin surface-mount outline with exposed pad (pin 2) tied to OUT terminal for improved heat transfer. Pin 1 = IN, Pin 2 = OUT, Pin 3 = NC (no connection).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AL5809-20Y-13 and NSI45020AZT1G, the AL5890-20Y-13 uniquely combines 400V capability, integrated thermal foldback, and tight ±2.0mA accuracy - making it the sole choice for robust, maintenance-free, high-voltage LED lighting where reliability and regulatory compliance are mandatory.

Availability

AL5890-20Y-13 is available at Aetrix Electronics and suitable for commercial downlights, emergency signage, and architectural accent lighting requiring stable component supply, long-lifecycle support, and RoHS-compliant sourcing.

Supply support for AL5890-20Y-13 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 company specializing in discrete, analog, and mixed-signal ICs, with emphasis on power management, signal integrity, and lighting solutions.

The AL5890 product line targets cost-sensitive, high-reliability LED lighting applications requiring simple, resistorless constant current regulation across wide input voltage and temperature ranges.

FAQ

Can AL5890-20Y-13 be used in AC-coupled LED circuits?

Yes - the AL5890-20Y-13 supports both AC and DC configurations. In AC applications, it is typically paired with a bridge rectifier and optional smoothing capacitor. Its 400V rating accommodates peak voltages from 230VAC mains (≈325V), and its 7V turn-on threshold ensures reliable conduction during each half-cycle. No additional biasing or startup circuitry is needed.

What is the maximum LED string voltage supported with AL5890-20Y-13 in SOT89 package?

While the device supports up to 400V input-to-output differential, the practical LED string voltage depends on thermal limits. With SOT89 on a 1"×1" 2oz copper PCB, max continuous power is 3.61W. At 20mA, that yields 180.5V across the device - so for a 350V input rail, max LED string voltage is ~169.5V (350V − 180.5V). Higher string voltages require larger copper areas or forced airflow.

Does AL5890-20Y-13 require external capacitors or compensation components?

No - the AL5890-20Y-13 is internally compensated and operates stably without external capacitors. Diodes' datasheet confirms stable operation across full input and load ranges with no added components. A small ceramic bypass capacitor (e.g., 100nF) near the IN pin is recommended for noise immunity but is not required for regulation stability.

How does thermal foldback behave under sustained high-temperature operation?

When junction temperature exceeds +130°C, AL5890-20Y-13 linearly reduces output current to maintain safe power dissipation. For example, at +140°C, current drops to ~18mA; at +150°C, to ~16mA. This preserves LED lifetime and eliminates thermal shutdown cycles - enabling graceful degradation rather than abrupt failure in enclosed or high-ambient environments.