Cross reference for ST part STCS1A CC led driver

Link for the above part is
www.st.com/.../stcs1a.html

Please clarify if the junction temperature or heat would be high compare to a normal buck IC.

does it need a separate DC-DC circuit and then can be connected along or can we give direct input from battery ranging from 12-30V?

Please clarify on this

Hello,

If your input range is 12-30 volts and is non-adjustable (such as a battery) and your LED load happened to be near 12 volts the efficiency at 30 volts would be 40%.  If the LED load is 12 watts 18 watts would have to be dissipated in the linear element when the input is 30 volts for a total power of 30 watts.  A buck converter would be around 90% efficient making the buck dissipation around 1.3 watts for a total power of around 13.3 watts.

If there is no control of the input voltage the efficiency will depend on the input voltage and LED stack voltage (excluding circuit power).

If you plan on using a DC to DC stage why not just create an LED buck driver from the battery unless the DC to DC stage is needed for something else?  TPS92515 is a fairly simple buck converter to drive LEDs, LM3409 if higher current is needed.

Thanks,

Thanks for the info Mr. Irwin.

If i am using LM3466 ic, does this IC need a separate DC-DC converter circuit and then can be connected along the load or other input OR we can give direct input from battery ranging from 12-30V (which is lead acid one).

Thanks.

Hello,

Using a linear from 12-30 volts doesn't really make sense unless the power level is very low. I would use the parts mentioned above, they are meant to run from battery (automotive) application. These are current regulators so you don't need to use a DC/DC converter to a linear.

Thanks,