In case there is a chance i need the pin later, maybe for some debugging, then I add a resistor. Else I connect it directely to GND.
(only with split GND planes, high power applications, or very noisy environment...maybe)
Technically i don´t think it has much benefit.
Circuits having high impedance inputs are prone to suffer with antenna effects along the routed tracks and the pull-down resistor ensure that some noise will be drained to the ground.
In case there is a chance i need the pin later, maybe for some debugging, then I add a resistor. Else I connect it directely to GND.
(only with split GND planes, high power applications, or very noisy environment...maybe)
Technically i don´t think it has much benefit.
Circuits having high impedance inputs are prone to suffer with antenna effects along the routed tracks and the pull-down resistor ensure that some noise will be drained to the ground.
Hi, could you advise some reference? Some of my friends said the pull-down resistor will make the pin to be susceptible to noise, because it is not at the same potential with the ground.
With high power, high current applications there is noise on the ground. And especially when you have split GND planes, there you will see ground bounce. If now the bounce voltage is so high (maybe onle short switching spikes) that internal protection diodes become conductive, then a resistor helps to limit the current.
In a circuit having for instance the gate of a CMOS transistor at input ( which impedance lies much above the range of houndreds megohms ), a pull-down resistor ensures that the smallest static electricity would be carried down to ground.
In a circuit having for instance the gate of a CMOS transistor at input ( which impedance lies much above the range of houndreds megohms ), a pull-down resistor ensures that the smallest static electricity would be carried down to ground.
This way you will not be able to use that pin as an input anymore. By using a pull-down resistor, you ensure that its voltage will not freely fluctuate at any logic level, but will stay at a predefined value.