what is push-pull output?

[banh]

I read datasheets and often faced with the term push-pull output? WHat is it?
Thanks.

 

[Nigel Goodwin]

I read datasheets and often faced with the term push-pull output? WHat is it?
Thanks.

It usually refers to the output stage of audio amplifiers, where one device handles the positive peaks and another handles the negative peaks. The region where they swap is called 'crossover', and a badly designed transistor amplifier can cause 'crossover distortion' at this point at low volumes.

 

[banh]

Don't quite understand. For example I read the MAX6501 datasheet, and it says MAX6501.MAX6503 have an active-low, open-drain
output while The MAX6502/MAX6504 have an activehigh,
push-pull output.

 

[Nigel Goodwin]

Don't quite understand. For example I read the MAX6501 datasheet, and it says MAX6501.MAX6503 have an active-low, open-drain
output while The MAX6502/MAX6504 have an activehigh,
push-pull output.

It's similar to an audio amplifier, in that you have two output devices - one connects between the output and +ve, turning this ON forces the output HIGH. The other connects between GND and the outout, turning this one ON forces the output LOW.

Often a logic output won't do this both ways, perhaps just having a transistor from output to GND, and relying on a simple resistor to pull the output high when the transistor is turned OFF. This is one reason for the 'fan out' limitations on some logic outputs.

 

[Exo]

It just means MAX6502 can both sink and source current, while MAX6501 can only sink current.

 

[banh]

thanks a lot!