Calculation Method.

[navinchandra]

I have made LED panels in which 4 LEDs are in series and such 45 series are placed in parallel.
I want to operate it with [u][b]CONSTANT CURRENT[/b][/u] LED Driver. There are many constant current drivers are available off the self. To select suitable driver I need to supply voltage and current of entire panel. [b]how to calculate the same[/b]. As per specification of the LEDs used, its voltage[i][b] Vf[/b][/i]=3.2v and [i][b]If[/b][/i] is 20mA. LEDs I have used are SMD. If need be, I can send schematic diagram, for which please grant permission.
Thanks.
NAM