LED AC LED driving circuit with current source of cascode type

摘要

In the present invention, in the AC LED driving circuit having the cascode structure, that is, the switching circuit portion of the cascode structure, the headroom voltage value of each switching circuit portion is kept constant, and the characteristics of the clamping element, The present invention relates to an AC LED driver circuit having a current source of a cascode structure that allows all switching circuits to always operate under the same conditions regardless of external temperature, An LED lighting unit including an n-th LED located at a longest distance from the power supply unit starting from a first LED located at a distance from the power supply unit; A plurality of switching circuit units forming a channel, And a voltage headroom control unit connected to the corresponding LED-to-LED connection line, wherein the voltage headroom control unit is separately installed in a connection line between the corresponding LEDs of the switching circuit units and the LED illumination unit, A plurality of clamp elements connected to the connection lines between the clamp elements and the switching circuit sections and receiving a node value for each of the clamp elements and receiving a bias value of a gate or a base of the clamp element, And a bias adjusting unit for adjusting a value of the bias voltage.