Q:
note you use the Tantalum capacitor as output capacitor, how about the loop stability if use ceramic capacitor(like as 5pcs of 100uF) as output capacitor?

 A:
To keep the ERM based power supply.....

 Q:
Can this ERM methode solve the ripple during no load condition?

 A:
Assuming you are talking about out.....

 Q:
Do you have Dc/Dc devices that convert input voltage of +15 or +5 to -5V?

 A:
The simple and better way for Conv.....