UCC28810 design configurations

Nidhi:

 

   Can you tell us more detail about the LED drivers you are designing? What is the input voltage ( 120Vac, 230Vac or univeral input )? What are the output LED voltage stack and current? Do you want to design one LED driver with output power varying from 10W to 50W or multiple LED drivers?

   Normally people do PWM dimming on two stage LED driver. You can use UCC28810 as the front stage for PFC and use a DC/DC LED driver to regulate LED current. There are many DC/DC LED driver IC with PWM dimming capability you can choose from TI.

 

David Zhang

David,

Thank you so much David for your reply.

Input Voltage is 85~230VAC. The LED voltage is between 36-50V. The wattage could be anywhere between 10-60W. So i actually want to know the calculations and parameters on the basis of which my design should be altered to get the Wattage i desire.AC-DC LED driver is what i have in mind. 

Nidhi

Nidhi:
If you are doing single stage AC-DC LED driver and the LED stack voltages are the same, you can get different output power by just changing the LED current sense resistor. You can start with the 60W design and the same design should work at lower power level. However if you want the design to be optimized at lower power level, you can change the transformer, EMI filter, MOSFET and output diode to shrink the size and lower the cost.
David Zhang

David,

What about variations in the current to change the Wattage?

Nidhi: The output power equals the LED stack voltage times the LED current.
David Zhang

David,

Aren't there any design notes with calculations pertaining to each component value. As in the thread for transformer design which you have given.

-Nidhi

 

Nidhi:

     Sorry, I cannot find a design note showing how to calculate each component value of an AC/DC power supply. Here is a pdf file showing how to design a flyback transformer.

      www.ti.com/lit/ml/slup127/slup127.pdf

 

David Zhang