question of negative voltage building methods

[rezaf]

Hi everybody
I want to make a negative voltage to control the zoom & focuse of my security camera and control the negative voltage with MCU. I want one component that converts the positive to negative voltage with any need of other components. any one know that what component I must use ?????????
I used from MAX232's VS+ and VS- pins but it's capacitors and ISIS software's problems to control supply of MAX with MCU is a difficult for me .
thanks for your help .

 

[mosheavi]

You dont mantion Vin/Vout Iout
Options:
1. https://focus.ti.com/lit/ds/symlink/tps63700.pdf
2. TPS54xx (5430/50)

 

[rezaf]

Thanks
my camera's zoom and focuse input voltage are in range of 3~13 V DC and low current about 500 mA .with negative voltage Zoom- & focuse- with positive voltage reverse.I want when push one of zoom- and focuse- button that connected to MCU the MCU pin high, and activate the component that convert positive to negative voltage then the camera with output of that and GND will go to zoom- or focuse- .

 

[rezaf]

I have attached a picture to understanding the purpose. I previously do this work in 3 form (in picture) .1-with transformer with centre tapped and relays. 2-with MAX232 and relays 3-with four MAX232 . but now I don't have enough space for this works and ISIS don't permission to control VCC pin of ICs with other component. 500mA is based on guesswork and are lower. my camera have 3 terminal in back of that named zoom com focuse .
thanks.