LinkSwitch-TN wide range power supply
Posted by: Quintin
on
I am using a Linkswitch-TN LNK302 in an industrial application that requires a worst case input supply voltage from 45.6Vac to 276Vac. The voltage will usually range from 57V to 230V. The circuit is configured in a buck-boost configuration generating negative 5V, the input AC is half-wave rectified. My circuit uses on average 50mA. I have built a few of these power supplies up and I can even get them to start as low as 20Vac. My concern is the PIXls design’s warning of a minimum of 70VDC input. I would like to know if it would be safe for me to use the Linkswitch-TN LNK302 with an input voltage as low as 45Vac.
Hi,
The LNK302 can be used for an input voltage as low as 50VDC(rectified voltage in case of AC input). While most of our parts can start at fairly low input voltages we guarantee a startup at a voltage as low as 50V accounting for variation in part parameters over time and batch to batch variation.
The maximum power capability of a device as indicated in the power tables on our datasheet are based on certain assumptions. The part therefore needs to be derated in order to use it under different operating conditions.
PIXLs will provide a warning for any voltage lower than 70V only because that is not a standard operating condition for most designs.
We strongly recommend that you verify the temperature of the LNK302 at the highest expected operating temperature and lowest operating input voltage to conform that the part is not overstressed.
Regards
PI-Sarek