CONSTANT CURRENT TYPE LED DRIVER CIRCUIT FOR LED STOPLIGHT

摘要

PURPOSE: A constant current driving circuit for a LED(Light Emitting Diode) traffic signal lamp is provided to prevent the successive LED defect by continuously supplying a constant current to other LED regardless of the defect of one LED. CONSTITUTION: A power voltage generation terminal(210) changes the output voltage of a SMPS(Switch Mode Power Supply) to a circuit power supply voltage. A constant voltage formation terminal(220) generates a constant voltage by using a bandgap constant voltage circuit(221). A constant current formation terminal(230) changes a constant voltage which is generated with the constant voltage formation terminal to a constant current. An LED output terminal(240) amplifies a current which is generated with the constant current formation terminal. An LED output terminal includes a plurality of high voltage transistors.