[SOLVED] Basic Controllers input and output.

[kenambo]

Hi, I am new to controllers. What is CMOS compatible input. Whats the need for it in controllers especially in digital electronics. pls reply.

 

[barry]

CMOS compatible means that a logic '0' is less than 0.3 x Vsupply, and logic '1' is greater than 0.7xVsupply.

 

[kenambo]

Thanks barry... Another question for you? What is the importance of giving this input to the devices?...

 

[hemnath]

For example, if you have connected a push button to your uC pin. Normally +5V will be going to uC pin through the pull up resistor. During this case, the voltage at the uC pin will be around +4.9V. When you press the push button, it wont be completely zero signal due to some leakage. During the cases, the signal will be around +0.5V. But still there is a signal on the path. To differentiate whether the push button is pressed or not, logic levels are used. This is just an example.

 

[kenambo]

Thank you Hemnath.. So that the processor operations are digital... Am i right?...

 

[hemnath]

yeah all the operations will be performed in digital. But can sense analog signal using ADC pins in micro-controller. Even that analog signals are converted to digital internally.