Simple, Constant-Current Linear Regulator Improves LED Current Tolerance

Diodes Incorporated's AL5809, offered in a robust two-terminal PowerDI®-123 package, 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-round higher performance than competitive alternatives or discrete circuit designs.

In 10k quantities, the AL5809 Constant Current Linear LED Driver from Diodes Incorporated is priced at: $0.10 USD each for the SOD-123 packaged devices, $0.11 USD each for the 15-50mA parts in the PowerDI-123 package, and $0.12 USD each for the higher current 60-150mA PowerDI-123 packaged devices.