Date: 20/10/2011

0.8V-30V rated LED driver delivers LED currents in the range of 20-100mA

Diodes Incorporated has announced the AL5802 linear LED driver. Integrating a high gain NPN transistor with a 30V rated pre-biased NPN output transistor for controlling current in up to 9 low-power series-connected LEDs. With an open-collector output capable of operating between 0.8V to 30V, the SOT26 packaged driver supports 12V and 24V power supplies and delivers LED currents between 20mA to 100mA for LED signs, lamps and automotive interior display applications.

Diodes Incorporated explains that LED current is set by an additional external low-value resistor, generates a reference voltage of 0.65V across the resistor and minimizes power losses, ensures supply voltage headroom with the internal high gain transistor. The negative temperature coefficient of the reference voltage means that LED current is automatically reduced at high temperatures, which protects LED and improve circuit reliability.

PWM dimming of the LED string is simple to achieve by either driving the device bias pin with a low-impedance voltage source or driving its enable pin with an external open-collector NPN transistor or open-drain N-Channel MOSFET. The AL5802's wide ambient temperature operating range of -40C to +125C enables it to be circuit mounted very close to the LEDs in space-limited lighting applications.

For further information, visit: www.diodes.com