Skip to Content
Digital Circuits & Design, 1st Education by Pearson
book

Digital Circuits & Design, 1st Education by Pearson

by D. P. Kothari, J. S. Dhillon
December 2015
Intermediate to advanced
1081 pages
38h
English
Pearson India
Content preview from Digital Circuits & Design, 1st Education by Pearson
14.30 | Chapter 14
A
1 kΩ
B
Y
+15 V
+5 V
+
339
V
i
FIGURE 14.26 | Interfacing an LM339 to a TTL input
14.9 | TTL DRIVING EXTERNAL LOADS
Because standard TTL can sink up to 16 mA, TTL driver can be used to control an external
load such as a relay, an LED, etc. Figure 14.27(a) illustrates the idea. When the TTL output
is HIGH, there is no load current. But when the TTL output is LOW, the lower end of R
L
is
ideally grounded. This sets up a load current of approximately
I
R
L
L
=
5V
Since standard TTL can sink a maximum of 16 mA, the load resistance is limited to a
minimum value of about R
L
= 312 Ω (5 V/16 mA).
B
A
R
L
C
+5 V
FIGURE 14.27(a) | TTL output drives
load ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

AirBnbBlueOriginElectronic ArtsHomeDepotNasdaqRakutenTata Consultancy Services

QuotationMarkO’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
QuotationMarkI wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
QuotationMarkI’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
QuotationMarkI'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Mark W.
Embedded Software Engineer

You might also like

Digital Systems: Principles and Design by Pearson

Digital Systems: Principles and Design by Pearson

Raj Kamal
Pulse and Digital Circuits

Pulse and Digital Circuits

Venkata Rao K., Rama Sudha K., Manmadha Rao G.

Publisher Resources

ISBN: 9789332559080