Diodes Incorporated – AL5809: Simple, Constant Current Linear Improves LED Current Tolerance

The new AL5809 is offered in a robust two terminal PowerDI®-123 package. It provides an improved accuracy, cost effective solution for constant current linear driving of LEDs.

With its 1.2W maximum power dissipation, excellent 20ppm/°C temperature stability and high power supply rejection ratio, the AL5809 delivers LED currents with a ±5% tolerance over a wide temperature range, greatly simplifying the solutions for its target applications of LED signage, LED strip lighting and low current retrofit lamps.

The AL5809 is specified for the -40°C to +125°C temperature range, with an operating voltage (between the two terminals) from 2.5V to 60V and is offered in various fixed output current versions; this removes the need for external current setting resistors. The PowerDI-123 package fixed output current options are 15mA, 20mA, 30mA, 40mA, 50mA, 60mA, 90mA, 120mA and 150mA, while in the alternative SOD-123 package there are current output versions of 15mA, 20mA, 30mA, 40mA and 50mA.

As well as meeting the needs of designs requiring a simple linear regulator (e.g., no inductor or external resistor), the AL5809 provides additional performance features, over-temperature protection (OTP) and the ability to drive both low and high side LED chains.

The AL5809 is a small footprint, low BOM cost LED driver that is simple to use and provides improved accuracy and all-around higher performance than competitive alternatives or discrete circuit designs.

Typical Applications Circuit

Typical Applications Circuit

Functional Block Diagram

Functional Block Diagram


  • Robust power package up to 1.2W for PowerDI-123
  • -40°C to +125°C temperature range
  • ±5% LED current tolerance over-temperature
  • 15mA, 20mA, 30mA, 40mA, 50mA, 60mA, 90mA, 120mA and 150mA available in PowerDI-123 package
  • 15mA, 20mA, 30mA, 40mA and 50mA available in SOD-123 package, and other current options available by request
  • Constant current with low temperature drift and high power supply rejection ratio
  • 2.5V to 60V operating voltage between two terminals
  • Available in PowerDI-123 and SOD-123

  • Offline LED lamps
  • LED power supplies
  • White goods
  • LED signs
  • Instrumentation illumination






Leave a Reply