Hello.
I'm having some trouble understanding how to properly maintain input logic levels on the 74LS04 inverter chip. TI says that unused inputs must be held at VCC or GND, using a resistor. I've got that, and I think I understand why a pull-up (or pull-down) resistor is needed. Where I'm getting stuck is the term "unused input".
I want to integrate this into a MIDI module. The inverter will be configured act as a buffer. If I power the MIDI module on, but do not have it connected to a MIDI signal, will the input gates "float" even when their pins are "used" in the circuit?
Also, how do I go about integrating the pull-up resistor(s)? Do I need one for every gate, or can I tie them all to one resistor?
Is 1.2K ohm enough resistance for the pull-up?
Thank you for your help.
I'm having some trouble understanding how to properly maintain input logic levels on the 74LS04 inverter chip. TI says that unused inputs must be held at VCC or GND, using a resistor. I've got that, and I think I understand why a pull-up (or pull-down) resistor is needed. Where I'm getting stuck is the term "unused input".
I want to integrate this into a MIDI module. The inverter will be configured act as a buffer. If I power the MIDI module on, but do not have it connected to a MIDI signal, will the input gates "float" even when their pins are "used" in the circuit?
Also, how do I go about integrating the pull-up resistor(s)? Do I need one for every gate, or can I tie them all to one resistor?
Is 1.2K ohm enough resistance for the pull-up?
Thank you for your help.