What different to push-pull and open-drain?

[starchern]

sometime i see the ic datasheet show the push-pull port or

the open-drain port. What different for this?

 

[olemp]

first circuit is pushh-pull..here you give supply voltage to the output or pull the output to gnd..

and second circuit open collector(if you use mosfet then open drain)..here you can just pull the output to gnd..

 

[jdhar]

You can connect multiple open-collector/drain devices together on the same line, but not multiple push-pull since they will try and drive eachother differently.

 

[devrimaksin]

The obvious difference
You cannot pull the output to Logic one with
open drain.

 

[IanP]

Terms and definitions on all output types:
**broken link removed**

 

[masoudk_81]

Hi

the first answer to your reply is almost right. you should
note that in push pull, tha output has voltage all the time , but in
open collector (or open drain in mosfets) the output stage only pulls
current (a good zero voltage) but when the base of transistor goes to
zero, the transistor gets off and the collector floats and has no voltage.
you can tight open collector outputs together in data buses.

masoud