for a project about sensors i need +5 volt and -5 volt. the max cuurent need for +VDD is 100 mA and for -VDD is 3 mA.
please, i am looking for the schematic of a good circuit for creating -5 volts from +5 volts.
you can use the famous circuit that you can find in any text book (art of electronics for example) that use center tap transformer and two types regulators 7805 and 7905
i have simple circuit can help you
but the out will be around -4.5 volt if your input clock +5 volt
i know the 4.5 volt make problem with you but this circuit is very simple