Clarrification on Schmitt-Triggered Input

Thread Starter

exzkrix.skidez

Joined Nov 16, 2018
6
Hi everyone,

I dont understand much about Schmitt-Triggered Inputs but would like to ask for clarification regarding with the datasheet I have read ( please see the attached file for the specific information). If I will apply 2V with 10mA signal to the SCLK pin, assuming that the supply of the device is 3V, will it cause some kind of damage due to excessive current input to the SCLK pin? If it will cause some kind of damage, what is the best solution for this problem.
 

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Thread Starter

exzkrix.skidez

Joined Nov 16, 2018
6
So, as long as the voltage level is in the range of 0 to 5V, even if i have to give 20mA current, the device will still works fine. Am I right?
 

Thread Starter

exzkrix.skidez

Joined Nov 16, 2018
6
You don't give it 20ma, the device sources/sinks current that is shown in the spec sheet. It's a voltage controlled device.
Yes, I know that it is a voltage controlled device but what buffles me is that the microcontroller that im going to use sources currents 10mA to 20mA with voltage levels 0 to 3.3V. The parameter "Input Currents" of the device says +- 10mA. I wonder if it has to do with current sinking. Will it fry the device if I use the microcontroller?
 

noweare

Joined Jun 30, 2017
115
The micro can source or sink up to that current. It is the device that determines how much the micro will give it. The device is high impedance so it will not take the 10 or 20 ma your talking about. If it was a resistor of say 150 ohms then it would draw 20ma from a 3.3 volt output.
 
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