What Does Tie Pin 1 High to Enable the Output Mean in Electronics?

[New Kid]

TL;DR

Enabling the output?

Hello,

I am new to engineering first year! I was wondering what "Tie pin 1 high to enable the output" My boss asked me to look at a crystal and asked me to do a small PCBA in PCB Express, but I am not sure what "high" is, is "high" tied to the +5V supply or is he asking for me to drop a pullup resistor? I would ask him again he is out on a honeymoon. Anything will help... Thanks!

 

[berkeman]

Welcome to PF.

Yes, "tie high" means to pull the input up to the supply rail. If the part is running off of 5V and GND, then pull that pin up to 5V. You can tie it directly to 5V with a trace, but a better practice is to pull it up through a medium-size resistor (10k-40k-ish). That allows testing of the enable/disable function in manufacturing, at the cost of one resistor. Your Manufacturing Engineering Department may have "Design for Manufacturability Rules" that will dictate whether you tie directly with a trace or through a resistor.

Always check the part's datasheet to be sure you understand the allowed supply voltages, input current specs, etc. Have fun learning!

 

[phyzguy]

It means to connect that pin to the high supply, which it sounds like is +5V in your case. It probably doesn't matter whether you connect it to the high supply directly (with a wire), or whether you connect it through a resistor. Do you have the datasheet for the component you are working with? It might have some info. The chip is probably designed so that you have to connect this pin to the high supply in order for the outputs to drive out data, this is what "to enable the output" means. This is often called 'Output enable", and an output using this is called a "tri-state buffer". See this link for example:
https://www.electronics-tutorials.ws/logic/logic_9.html

 

[berkeman]

(Great minds think alike)

 

[New Kid]

Interesting! Makes sense. since this is my first board spin I am anxious to get his done! Thanks for your assistance!

 

[Baluncore]

"Tie pin 1 high to enable the output"

That statement refers an input logic signal that needs to be connected to a high = positive logical 1, to enable the outputs. That could be a positive supply, or it could be to some other logic signal that remains high = 1.