Hi,
    iam kind of novice to circuit design. I wish to design a push pull amplifier with single supply. I understand the push pull configuration for dual supply. I simply not getting the concept for single supply.

In single supply, at maximum my input voltage can be vdd--ground. In that case what does postive and negative cycle of input means? For example in a 3.3 v supply if i assume a sine wave is riding on VDD/2 as my input, then both of my transistors are in ON from VDD-VTHP to VTHN in one direction and vice versa in the other direction. There where is push pull action here? In other wrds i was unable to see the push and pull currents for negative and positive half cycles and what iam seeing is short circuit current from vdd- gnd when i probed at PMOS and NMOS transistors.

To be honest i dont know how to see the push pull currents. Am I needed to connect my load resistor from output to VDD/2 or to ground?

If some one can explainin me the transient action with sine wave as an input, i would greatly appreciate you.

If my question sounds silly,plz excuse me.

Thanks in advance

Hi Chase,
              My thanks for your reply. I Understand your explianation of ac ground concept but still unable to see the pushpull currents after connecting end of resistor to VDD/2.

well, iam trying to simulate the circuit in spice engine. Exactly my circuit is an inverter with shunt feed back. My load resistor is connected between output node and VDD/2. COuld you please elobrate me how should i setup my simulation to probe the push and pull currents.

Also you mentioned, its different if the load is cap-- how does circuit work in this case. If you feel short of time to explain lease refer some document/notes which is with single supply.

Thanks in advance