Diodes Incorporated AL5890-20D-13

Overview

AL5890-20D-13 from Diodes Incorporated is a 400V constant-current linear LED driver in TO252 (Standard) package, delivering a factory-trimmed 20mA output with ±1.5mA typical accuracy over −40°C to +105°C ambient. It supports both high-side and low-side LED string configurations, features thermal foldback activation at +130°C junction temperature, and operates with a minimum turn-on voltage of 7V across IN–OUT terminals. It is used in commercial LED lighting fixtures requiring stable current regulation without external resistors.

For engineers reviewing the AL5890-20D-13 datasheet, AL5890-20D-13 pinout, AL5890-20D-13 application, or AL5890-20D-13 equivalent, this page provides verified technical context, package-specific thermal data, real-world current accuracy curves, thermal foldback behavior, and validated alternative options for 20mA LED driving in AC/DC lighting systems.

Technical Context

The AL5890-20D-13 implements a bandgap-referenced linear regulator architecture with internal current-sense resistor (RCS) and voltage-controlled current source. Its functional block includes a precision reference, error amplifier, and pass transistor - all integrated into a single die with no external feedback components required.

It operates as a two-terminal current regulator: current flows unidirectionally from IN to OUT, with turn-on triggered when VIN−OUT exceeds 7V. Thermal foldback initiates at TJ = +130°C, linearly reducing output current to limit power dissipation under sustained high-temperature conditions.

Key Specifications

Pinout & Package

AL5890-20D-13 is housed in TO252 (Standard) package - a thermally enhanced surface-mount outline with exposed pad for heatsinking. The package measures 6.10mm × 6.58mm × 1.59mm and features a copper-exposed thermal pad (pin 2) connected internally to the die substrate.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AL5809-20D-13 and NSI45020AZT1G, the AL5890-20D-13 uniquely combines 400V operation, factory-trimmed 20mA accuracy, and active thermal foldback - making it the only option qualified for thermally demanding, high-voltage commercial lighting where reliability and safety certification are mandatory.

Availability

AL5890-20D-13 is available at Aetrix Electronics and suitable for commercial LED downlights, architectural linear lighting, emergency exit signage, and industrial control panel indicators requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AL5890-20D-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 manufacturer specializing in discrete, analog, and mixed-signal solutions, with design centers in Asia, Europe, and North America and ISO/TS 16949-certified manufacturing facilities.

The AL5890 product line delivers cost-optimized, two-terminal constant-current drivers for AC- and DC-powered LED lighting, targeting applications where simplicity, thermal robustness, and regulatory compliance are prioritized over digital programmability.

FAQ

What is the maximum LED string voltage supported by AL5890-20D-13?

The AL5890-20D-13 supports up to 400V across its IN–OUT terminals. For a typical white LED with Vf ≈ 3.6V, this allows up to 110 LEDs in series. Actual limit depends on thermal performance: at TA = +60°C and no heatsink, power dissipation must stay below 2.1W (based on θJA = 26.12°C/W and TJmax = +125°C), constraining practical string voltage to ~280V in enclosed fixtures.

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

Yes - the AL5890-20D-13 is commonly used in rectified AC configurations. It requires a bridge rectifier and bulk capacitor; the device regulates current during both half-cycles when VIN−OUT exceeds 7V. Designers must ensure peak reverse voltage across the IC does not exceed 425V (absolute max), and include appropriate surge suppression per IEC 61000-4-5.

Does AL5890-20D-13 require an external heatsink?

Not necessarily - the TO252 package's exposed pad provides sufficient thermal conduction when soldered to ≥25.4mm × 25.4mm of 2oz copper. In open-air conditions at TA = +40°C, it sustains full 20mA output up to 320V drop (6.4W). For enclosed fixtures above +60°C ambient or >300V operation, a small external heatsink or thermal via array is recommended to maintain TJ < +125°C.

How does thermal foldback affect light output in AL5890-20D-13?

When junction temperature exceeds +130°C, AL5890-20D-13 linearly reduces output current - e.g., at +140°C, current drops to ~15mA; at +150°C, to ~10mA. This preserves LED lifetime and prevents catastrophic failure but causes measurable lumen reduction. Designers should use thermal simulation to ensure foldback activates only during rare fault conditions, not normal operation.