I want to use WS2811 to drive high current LEDs. As it is mentioned in the datasheet this chip provides 3 channels with 18.5mA constant current sinks. Maybe what I need is a simple PNP BJT with constant amplification factor of 18 (18.5*18=333mA for 1W LED) like the circuit below

^{simulate this circuit – Schematic created using CircuitLab}

But I know there is no such BJT with fixed beta. Is there any simple circuit that can do just that? (I'm just a hobbyist, excuse me for any mistakes)