AL5801 100V, ADJUSTABLE CURRENT SINK LINEAR LED DRIVER Description Pin Assignments The AL5801 combines a 100V N-channel MOSFET with a pre- (Top View) biased NPN transistor to make a simple, small footprint LED driver. The LED current is set by an external resistor connected from R EXT pin (4) to GND pin (6). The internal pre-biased transistor develops approximately 0.56V across the external resistor. The AL5801 open-drain output can operate from 1.1V to 100V enabling it to operate 5V to 100V power supplies without additional components. PWM dimming of the LED current can be achieved by driving the BIAS pin (1) with an external, open-collector NPN transistor or open-drain N-channel MOSFET. The AL5801 is available in a SOT26 package and is ideal for driving LED currents up to 350mA. SOT26 Features Applications Feedback Pin Reference Voltage V = 0.56V at +25C RSET -40C to +125C Temperature Range Linear LED Drivers 1.1V to 100V Open-Drain Output LED Signs Negative temperature V co-efficient automatically reduces RSET Offline LED Luminaries the LED current at high temperatures Low thermal impedance SOT26 package with copper lead frame Lead-Free Finish RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. Green Device (Note 3) Qualified to AEC-Q101 Standards for High Reliability Notes: 1. EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. All applicable RoHS exemptions applied. 2. See AL5801 Pin Descriptions Pin Pin Function Number Name 1 BIAS Biases the open-Drain output MOSFET 2 FB Feedback pin 3 OUT Open-Drain LED driver output 4 R Current sense pin. LED current sensing resistor should be connected from here to GND EXT Compensation pin. Connect COMP pin to REXT pin and insert a 1nF ceramic capacitor from COMP 5 COMP pin to FB pin for improved transient stability 6 GND Ground reference point for setting the LED current Functional Block Diagram Figure 1 Block Diagram Absolute Maximum Ratings ( T = +25C, unless otherwise specified.) A Symbol Characteristics Values Unit Output voltage relative to GND 100 V V OUT BIAS voltage relative to GND (Note 4) 20 V V BIAS FB voltage relative to GND 6 V V FB COMP voltage relative to GND 6 V V COMP V REXT voltage relative to GND 6 V REXT I Output current 350 mA OUT T Operating junction temperature -40 to +150 C J Storage temperature -55 to +150 C T ST Note: 4. With pins 5 and 6 connected together. These are stress ratings only. Operation outside the absolute maximum ratings may cause device failure. Operation at the absolute maximum rating for extended periods may reduce device reliability. 2 of 11 July 2012 AL5801 Diodes Incorporated www.diodes.com Document number: DS35555 Rev. 3 - 2