Hello Picsters,

thanks for your responses so far, but there is a significant misspelling
in my first question. Unfortunatelly, I was looking at the  pinout of a
wrong CMOS chip (it's a bit late, maybe I should go to bed :-) ), so I
have to ask the corrected question again:

>> I want to build a negative voltage generator with a CD 4009 (2 diodes
and a capacitor), the clock-impulses come from a ICL7107, which needs
the negative voltage. There are no problems with the schematic, but when
I look at 4009-data sheet, there are three supply (?) voltages:

- Vdd which is the regular power supply
- Vss this pin is to be tied to the GROUND
- Vcc : (Pin 1) CONNECT TO WHAT VOLTAGE? (I only need the driver ability
of this
chip)

Shall I tie Vcc to +5V or to GND, and what is the meaning of Vcc?


Thank you very much for your patience!

Markus
mailto:maro0019@stud.uni-sb.de