Hi, im designing 100mA constant current source using ST1CC40DR led driver
Specs as follows :
Input voltage : 12V
Iled(load current) : 100mA
Fsw = 850kHz
Load: 100 ohm
Assuming 5% ripple current, i.e 5mA
The drop across the Rs (feedback resistor) will always 100mV. So the Rs = (100mV/ Iled) = 1 Ohm
Vout = Voltage drop across 100 Ohm and 1 Ohm = 10V + 0.1V = 10.1V
Duty cycle = (Vout/ Vin)*100% = (10.1/12) 8 100% = 84.1%
Ton = 0.989us & Toff = 0.186us
From eqn. 20 (refer page number 21 in the datasheet)
L = (Vout/ Ripple current)*Toff
L = 0.37mH
Cout = 10uF
I tried simulating the design using the eDesign suite, in which the L&C values are automatically generated by the tool. But when I calculated theoretically by referring to the datasheet, L&C values are not matching with the values generated in the simulation eDesign tool. Pls suggest a solution how to select L&C values in the eDesign tool according to the theoretical calculation.
Can you provide a LT spice model for the IC for further simulation?
