TIDA-00129 Isolated PS Ref.Des.
A very good Reference Design from TI – Isolated Power Supply for PLC and Data Acquisition: http://www.ti.com/tool/TIDA-00129 Based on a LM5017, a wide Vin Buck Regulator: http://www.ti.com/product/lm5017 Datasheet: http://www.ti.com/lit/gpn/lm5017