12 V and -5V supply ICs

Hi all.

            I need to design a power supply circuit for the following requirement:

           1. 12V , 50mA

           2. 5V , 200mA,

           3. -5V , 50mA

         7.5 V , 500mA is available as a source. I am looking for a single chip or double chip solution.

single chip :- all the required supplies will be generated by a single IC

Double chip- 5V and -5V will be generated by one IC and 12 V will be generated by the other IC.

Kindly give the possible IC part no.. If possible please provide the circuit diagram also.

Other solutions are also welcome.

Thank you !

With very best regards

Jayant