LM5020: Flyback transformer design related

Part Number: LM5020



I am  designing Isolated DC-DC converter using Flyback topology with LM5020 PWM controller, could you recommend reference documents related to Flyback transformer design and

PWM controller with similar features to the LM5020 but at a lower price.

Input Voltage Range  36-75Vdc
Nominal Voltage  48Vdc
Input current (Full load) 252mA
O/p voltage 12V
O/p current: 833mA
Wattage 10W
Isolation 1.5kvdc
Switching Frequency  100kHz
Operating Tempertaure  -40 to 85 °C
Efficiency 85%
Linear Regulation   ±0.2 to ±0.5%
Load Regulation  ±0.5 to ±1%
Cooling Method Free air convection 

Thank you