12w LED driver circuit using LNK405EG driver IC
This LED driver circuit design is based on the LNK405EG driver IC and will provide a 12 watts output power . This LED driver circuit based on the LNK405EG driver IC accepts a wide range input voltage between 90 and 265 VAC and will provide a fixed output voltage of 36 volts at a 330mA constant output current . This constant current LED driver electronic project has a very high efficiency , more than 85% , typically 87% .
As you can see in the circuit diagram , this electronic project require few external electronic parts and can be very easy designed .
The LinkSwitch-PH provides high power factor in a single-stage conversion topology while regulating the output current in a wide range of input and output voltage variations typical in LED driver application environment .
Capacitor C1, C2, and differential choke L1, and L2 perform EMI filtering while maintaining high-power factor.
Resistor R1 and R2 were used to damp the resonance of the EMI filter, preventing peaks in EMI.
The buck power circuit with floating output connection composed of U1 (power switch +
control), D2 (free-wheeling diode), C5 (output capacitor), and L3 (output inductor). Diode D3 was used to prevent negative voltage appearing across drain-source of U1 especially near the zero-crossing of the input voltage. Diode D1 and C3 detect the peak AC line voltage. The voltage across C3 along with R3, R4, and R5 sets current fed into the V pin.
This current is used by U1 to control line undervoltage (UV), overvoltage (OV), and provide feed-forward current which in conjunction with the FEEDBACK pin current provides constant current to the LED load.