Application of open-drain driver

Hi,

Can anyone tell me the application of open drain driver ?

Just like any fast on/off switch. Basically just like a BJT, exept that you don't need a resistor as current limiter to the gate.

open drain driver has two output values: high Z and low. for example you can make a wired-or by using open drain configuration to make an interrupt mechanism. it is realized by a mosfet or a bjt

say you have some components connected to a microcontroller and you want the microcontroller to check if any of these components need attention. so you make a circiuit as follows:
you have a wire. this wire is connected to vdd through a resistor. and you have the open drain connections of multiple components connected to this wire also.when a devide does nort need attention, it gives low to the input of its open drain. when all the inputs to the open drain configurations are low, you have high impedance at the output, as if it was an open circuit. so there is no current flow from vdd to gnd and the wire has vdd on it. hovewer when the input to the open drain of at least one component is high(i,e. one of the devices says I need help), then the open drain gives low(gnd) as output. so the wire sees a way to gnd from vdd through the resistor and thus the wire becomes low. so the microcontroller that is taking this wire as input, sees a transition from vdd to low and this indicates that at least one of the components needs attention.

so open drain can be used to make wired-or circuits which can be used as an interrupt mechanism.