Dear listmembers

Sorry for this OT, so please answer me privately.

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
- Vee : CONNECT TO WHAT VOLTAGE? (I only need the driver ability of this
chip)

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

Thanks for your time and the bandwidth !!!

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