Negative and Positive VDD

[mems123]

Hi,

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.

thanks for any help,

 

[C-Man]

For creating -5V from +5V i have been using ICL7660 for years, works without any problem and could not be much simpler

**broken link removed**

best regards

 

[Al Farouk]

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

 

[mems123]

thanks for you response,

i have tried this IC, but there is a problem as below.
the negative voltage supply shifts to -4.5 volts.

mems123

 

[mems123]

we don't want to use transformers due to it takes many space on the PCB.

 

[ynhe]

Hi
As -5V output current is not large,Usually I use CMOS Charge Pump Inverter.This is the simplest way.
For example CAT660.

 

[mems123]

Thanks for your response.
the cat660 is simillar to 7660. again we have the problem of voltage level shift.

 

[sokrat]

HI all

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

THANKS

S 8O KRAT