Hi, this is the functional block diagram of a hall sensor IC. Can anyone please explain what is the purpose of these schmitt trigger followed by another trigger? Is single trigger cannot be able perform the function required?

 

Can anyone please explain what is the purpose of these schmitt trigger followed by another trigger? Is single trigger cannot be able perform the function required?

hi sit,
The 1st is a Comparator, with hysteresis, the 2nd is a Schmitt triggered by comparing input voltage against a Vref voltage.

E

 

I think that the first is a mislabelled differential amplifier. That would make a lot more sense.
What‘s the point of a comparator if its input can only be 5V or 0V?

 

hi sit,
The 1st is a Comparator, with hysteresis, the 2nd is a Schmitt triggered by comparing input voltage against a Vref voltage.

E

Got it Thank you

 

I agree with Ian0.
It makes little sense to have a comparator with hysteresis (a Schmitt-trigger) in series with another Schmitt-trigger.
I think the amp ahead of the Schmitt-trigger is supposed to be a differential amp (reverse the + and - input polarities) to sense the sensor differential signal, which has a DC offset.
The "Offset Cancel" block refers to the function the differential circuit performs.

 

View attachment 286631

Hi, this is the functional block diagram of a hall sensor IC. Can anyone please explain what is the purpose of these schmitt trigger followed by another trigger? Is single trigger cannot be able perform the function required?

Also
remember, its a picture done to describe the action of the chip,
drawn by an artist .. not an engineer,
its purpose is to easily convey that the input detects a difference, and the output has been made a good edge,
Id be surprised if you could look at the silicon if there were these actual components.

 

What has happened to the internal circuit diagram that always used to be on the datasheet of every IC?

 

Newer parts are so complex that an internal block diagram, or an "effective" circuit diagram is easier to understand.