Help me with biasing of npn push-poll stage

[MHML]

push-poll stage

please help me for biasing of all npn push pooll stage
This mean's that all of transistors must be npn.
Also output stage maked with power transistors (with low beta)

 

[cetc1525]

push-poll stage

I think the structure in opamp will be useful.

 

[vdaniel]

Re: push-poll stage

In attachment there is a very classic schematics of NPN output stage with
thermal coupled biasing. Q1, Q3 and Q5 should be mounted on the same heatsink.
The resistors values depend on the power and transistors used.
Whis R1 you trim the output stage biasing current trading between minimal current and minimal signal distorsion.

Varuzhan

 

[Borber]

Re: push-poll stage

The above circuit is wrong. Q4 should be PNP type.
Question: what kind of signal you want to apply to input? Is it square wave or analog audio signal?

 

[vdaniel]

Re: push-poll stage

Yes, I am sorry, corrected file in attachment.

Varuzhan

 

[vdaniel]

Re: push-poll stage

I am sorry again. First for twice attachment of the same file and second because the schematic contains one PNP transistor.

Varuzhan