What am I missing? The layout using the 3007 sends +9V to pin 1 of the 3007 (ground) and ground to pins 4 and 5 (Vgg and Vdd). This gives the required (relative) negative Vdd/Vgg to the 3007.
If you reverse +9v and ground for the 3207 circuit you get the required positive Vdd/Vgg but it also reverses the voltages on the 4558 and 4016. How do the 4558 and 4016 work with a negative power supply?
- The voltage pin reverse is only for the MN3207 (which is N-channel instead of P-channel internally). You don't need to reverse voltage on anything else. You just have to remember that MN3207 is opposite in its polarity from MN3007 in a negative ground circuit.
- Couple other points - output mixing in MN3007 is usually done in conjunction with a pullup resistor whereas with MN3207 it should be pulldown (IOW supply vs. gnd).
- VGG with MN3207 is calculated as 14/15 the supply voltage.
- With MN3007, VGG is the inverse: Vgg=
1-V(14/15), where V is your supply voltage. Correction, I meant to say V-V(14/15) which is V(0.067). Hopefully I got that right this time.
- Same goes for MN3005/MN3205
Caveat - this is what I remember off the top of my head but I still get confused with these even after using them both for more than a decade. If I'm wrong I'm sure someone else can correct.
