# everything I need to know about IC 74LS14?

My teacher asked for us (max until next 5 days) to tell her:

• General details about this IC (7414),

• Its features and benefits,

• Its application,

• Its important electrical characteristics,

• and everything that you surmise important about this IC that must I point out.

I read its datasheet but I didn't understand its description. Can you please tell me in a simple language (for example, I didn't understand Schmitt trigger function and what a jitter-free output signal is). In addition, please explain page 1 of 74LS14 Datasheet.

• What's the name of the part number, and model number? It's a lil vague to say 7414...Is it 74LS14 a Hex Inverter? Commented Oct 8, 2013 at 12:19
• Neither of those links went to datasheets. Commented Oct 8, 2013 at 12:49
• "Please explain everything about everything to me." - Sorry, -1, too vague. Commented Oct 8, 2013 at 17:20

## 1 Answer

An Inverter aka NOT gate is a fundamental block in Logic Design for Digital Circuits. It's purpose is to invert the signal. So,

• if input is Low (Logic 0), then the output will be High (Logic 1).
• if the input is High (Logic 1), then the output will be Low (Logic 0)

An example of an application is using it to Counting the number of 0's When using half adders block to add inputs, it cannot add zeros, since 0 + 0 = 0; So we want to invert them in order to quantify them. Now there are many many applications and ways to use inverters.

Some important electrical characteristics are the Logic High. What is it capable of transmitting for Logic 1?

Some chips transmit signals Low = 0 V, and High = 3.3V whereas others transmit Low = 0V and High = 5V (not to say these are the only types that exist) So understanding the signal transmission of LOW Level $V_{OL}$ and HIGH Level $V_{OH}$ capability is highly essential. It looks like this particular IC works with signals roughly around 0-3.3V. Don't get me wrong though, all electrical characteristics are there for a reason, and are essential in their own way.

As far as Input type, there are various types of Inputs (i.e. CMOS, BiCMOS and TTL), one of which is Schmitt. Its benefit is squaring off the edges of a signal to make up for slow rise/fall signals.

Figure 1. Non-Inverting Schmitt Trigger Signal. Top Signal is Input-Signal, Bottom Signal is Output-Signal

Figure 2. Inverting Schmitt Trigger Signal. Top Signal is Input-Signal, Bottom Signal is Output-Signal

Lastly, The first page should always contain the general description of the device to explain what it is. Which is, it contains 6 NOT Gates circuits. It also mentions the existence of Hysterisis, if you want to get more into Electromagnetics it is a electric displacement field of a ferroelectric and ferromagnetic material, but translation for this case it "increases the noise immunity and transforms a slowly changing input signal to a fas changing"

Two important notes are Function Table which explains the input-output relationship, as I described initially, (If A is 0 then Y is 1, if A is 1 then Y is 0) As noted by the equation, the bar above A stands for NOT. (Y = NOT A)

The second note on this page is the Conection Diagram which is there to tell you where (and what pin) to put input signals and measure their outputs. $A_i$ corresponds to $Y_i$ (i.e.$Y_1$ = $A_1$, so input signal can be processed through pin 1, and output measured through pin 2)

• Echad : YES . 74LS14 HEX SCHMITT TRIGGER Inverter . Commented Oct 8, 2013 at 12:46