How do you ground an output or input of a Logic IC chip , that is safe?
DO NOT SHORT A CMOS LOGIC HIGH OUTPUT TO GROUND!
So shorting the output of an Logic IC that has a HIGH state will cause HEAT and will damage the Input of the next logic IC chip?
I am talking about destroying a Cmos
output that has a datasheet that says its maximum allowed output heating for one output is 100mW.
Lookup the maximum allowed heating for the output of an old TTL IC yourself. I think it gets the hottest when its output is trying to go low but something shorts it to the +5V supply.
it will exceed the maximum allowed on the output and damage the output and the input of the next IC chip?
Why are you talking about damaging an input? It is the output that produces a high amount of heating when it is high and something shorts it to ground.
When the logic level High state is higher than +5 volts. And the circuit designer wants a logic high to be +15, the current is higher on the outputs of the logic IC chips
A Cmos logic IC uses Mosfets that HAVE NO INPUT CURRENT. Normally the output of a Cmos logic IC drives the input of another Cmos logic IC WITH NO CURRENT.
Any reason why they want a higher current?
They do not want. Instead the available current can quickly charge the capacitance of the pcb and the capacitance of the input it is driving.
The available current is higher when the supply voltage is higher because that is how Mosfets work. A higher gate voltage results in a higher output current.
Look at the graph I posted of Cmos output current again. With a 15V supply the shorted to ground output current is 26mA.
Then look at when it has a 5V supply. The shorted to ground output current is only 4mA.
Some manufacturers rate the maximum supply voltage at 22V. Then the shorted to ground output current is very high.
Guess how little is the output current when the supply is 3V.