The linear constant current regulator is a simple, economical and robust device designed to provide a cost effective solution for regulating current in LEDs, this type can set the current by a resistor as you need. It has a PWM pin can accept the Dimming control for on/off.

The constant current regulator is based on special technology and regulates current over a wide voltage range. It is designed with a negative temperature coefficient to protect LEDs from thermal runaway at extreme voltages and currents.
The constant current regulator turns on immediately  with only 0.3 V Vak. It requires two resistor to be designed as a high or low side regulator. The high anode-cathode voltage rating withstands surges common in Automotive, Industrial and Commercial Signage applications. One resistor is supply the power to IC and protect the circle without Shorter or Spike impact, and the other Resistor was used to set the current over the LED.