Diffference between Totem pole and push pull outputs

[myatham]

Hello All,
My design needs to connect 4 outputs of an IC to drive single RESET pin. I do not have open dran/collector output pins available. Can i use push pull or totem pole outputs pins (all tied together to drive RESET input of another MCU? What is the difference between Totem pole and push pull outputs?

 

[HTA]

Hello Myatham,

Open collector or open drain means that the output have only one transistor to ground and can therefor only pull an output to a low level. This allows you also to "wired-or" outputs(four in your case) together. If you have 3-state output you can use the enable output(with a low on the input) to function like an open collector output. If not you could use a push-pull output with a diode in series to allow only that a low level is given after the diode. This however adds the forward voltage of the diode to the low level. You may search also for "NPN/PNP/PP outputs" to research deeper into options.

Enjoy your design work!

 

[myatham]

Hello Myatham,

Open collector or open drain means that the output have only one transistor to ground and can therefor only pull an output to a low level. This allows you also to "wired-or" outputs(four in your case) together. If you have 3-state output you can use the enable output(with a low on the input) to function like an open collector output. If not you could use a push-pull output with a diode in series to allow only that a low level is given after the diode. This however adds the forward voltage of the diode to the low level. You may search also for "NPN/PNP/PP outputs" to research deeper into options.

Enjoy your design work!

Thanks for your reply.
It is good idea of implementing wired-OR by using an addtional diode at each output (Push-Pull).
Do you mean that both Totem-pole and push-pull I/O are same or any differences between?

 

[HTA]

Hello Myatham,

in the function there is not difference.

Enjyo your design work!