How to tell if a pin is floating? Is it shown in the schematic?

天天处于战斗状态

How to tell if a pin is floating? Is it shown in the schematic? [Copy link]

Or is it connected to the circuit to see the high and low level changes? If it does not receive the level, it is floating? Can all unconnected pins be called floating pins? Can anyone explain this?

秦天qintian0303

I don't understand what you mean. Generally, pins that are left floating are useless. Why do you want to test them?

maychang

[Can all unconnected pins be called floating pins? ]

Pins that are not connected to any circuit are of course floating pins.

However, it is not allowed to leave the input pins of digital logic chips using MOS technology floating.

天天处于战斗状态

Qintianqintian0303 posted on 2023-9-19 11:31 I don't understand what you mean. Generally, the pins that are left floating are useless. Why do you want to test them?

If not, I'm curious what this pin looks like in the schematic.

wangerxian

The voltage level of a floating pin is random.

led2015

Floating pins may cause some problems such as unstable level, increased sensitivity to electrical interference, etc. To avoid these problems, it is usually recommended to connect the floating pins to the correct voltage or signal source, or to turn them off or pull them low/high when designing the circuit.

zhaoyanhao

The pin is hanging in the schematic diagram as if there is no connection. The standard way to draw it is to add a hanging mark, that is, a cross. All software has this function

chunyang

The floating pins can be left unmarked in the schematic diagram or marked as NC. Whether the pins can be left floating is another matter.