LNK306 at 60 v in.
I am considering a LNK306D or LNK304D for an application where it will get it's power from a DC supply. Voltage will vary from 50 to 90 volts. I need 15 volts out at about 120 ma. There seems to be some warnings in spec sheet and in the design software about the supply dropping below 70 volts. Are these parts suitable for operation at supply voltages this low? I prefer this device because I don't need isolation and would prefer the simplicity of a single winding inductor.
Comments
Thanks for your answer. I have another question - the design software and spec sheet specify a RMS current for the inductor but do not specify saturation currents. For an output current of 120 ma what is the saturation current requirement?
Hi,
The LNK306 regulates by skipping cycles. Each cycle has a peak current as high as 647mA depending on di/dt (see datasheet page no.10)
It is required that the inductor should not saturate at this current.
Regards
PI-Sarek
Hi,
Yes, you can use this part for operation down to a voltage of 50V. Operation below that level is not guaranteed though most of our parts will work beloiw that voltage as well.
The power table in the datasheet is made based on certain assumptions regarding typical input voltage. Since your voltage is lower than these limits, the spreadsheet is providing a warning.
As long as device parameters are not exceeded you should be able to use the part as suggested. The power level may have to be slightly lower than the one indicated in the power table on the front page of the datasheet. If you need any help with the design, you should contact our sales office in your area and an applications enginbeer should be able to help you further.
Regards
PI-Sarek