Quantcast BANDWIDTH OF AN AMPLIFIER - 14180_55

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
2-3 Figure 2-1.—Frequency response curve of audio amplifier. Notice in the figure that the lower frequency limit is labeled f1 and the upper frequency limit is labeled f2. Note also the portion inside the frequency-response curve marked "BANDWIDTH." You may be wondering just what a "bandwidth" is. BANDWIDTH OF AN AMPLIFIER The bandwidth represents the amount or "width" of frequencies, or the "band of frequencies," that the amplifier is MOST effective in amplifying. However, the bandwidth is NOT the same as the band of frequencies that is amplified. The bandwidth (BW) of an amplifier is the difference between the frequency limits of the amplifier. For example, the band of frequencies for an amplifier may be from 10 kilohertz (10 kHz) to 30 kilohertz (30 kHz). In this case, the bandwidth would be 20 kilohertz (20 kHz). As another example, if an amplifier is designed to amplify frequencies between 15 hertz (15 Hz) and 20 kilohertz (20 kHz), the bandwidth will be equal to 20 kilohertz minus 15 hertz or 19,985 hertz (19,985 Hz). This is shown in figure 2-1. Mathematically: You should notice on the figure that the frequency-response curve shows output voltage (or current) against frequency. The lower and upper frequency limits (f1 and f2) are also known as HALF-POWER POINTS. The half-power points are the points at which the output voltage (or current) is 70.7 percent of the maximum output voltage (or current). Any frequency that produces less than 70.7 percent of the maximum output voltage (or current) is outside the bandwidth and, in most cases, is not considered a useable output of the amplifier. The reason these points are called "half-power points" is that the true output power will be half (50 percent) of the maximum true output power when the output voltage (or current) is 70.7 percent of the maximum output voltage (or current), as shown below. (All calculations are rounded off to two decimal places.) As you learned in NEETS, Module 2, in an a.c. circuit true power is calculated using the resistance (R) of the circuit, NOT the impedance (Z). If the circuit produces a maximum output voltage of 10 volts across a 50-ohm load, then:


Electrical News
EEVblog #644 – How To Design Front Panels On Extruded Enclosures – µSupply Part 14
Dave shows some techniques on how to build and mount...
eevblog.com
Silicon Photonics Acquires Key Subsystems
Silicon photonics will someday replace the expensive gallium arsenide photonics...
eetimes.com
Apollo 11 Inspired Generations of Innovators
Neil and Buzz were on the moon. Orbiting above, there...
eetimes.com
Smartwatches Suck, Says Pebble Backer
There are only two significant platforms in the smartwatch arena...
eetimes.com
Future Engineers: Don't 'Trip Up' on Your College Road Trip
A future engineering student gives his advice on making the...
eetimes.com
Future Engineers: Don't 'Trip Up' on Your College Road Trip
A future engineering student gives his advice on making the...
eetimes.com
DARPA's Chip Office Reboots to Tackle Cost & Complexity
DARPA's Microelectronics Technology Office, the source of much chip innovation...
eetimes.com
Mentor Launches Xpedition PCB Data Management Solution
The new Xpedition data management solution will ensure flow-wide PCB...
eetimes.com
Juggling a Cornucopia of Projects
Max is juggling so many hobby projects that it's no...
eetimes.com
Develop & Share Open-Source Hardware Projects
Matlab and Simulink are finding use in projects that don't...
eetimes.com
Android Open-Source for ARMv8-A Starts 64-Bit Avalanche
Mobile devices will need a big boost in processing power...
eetimes.com
Find an Entrepreneurial Mentor
As Luke had his Yoda, so does a startup CEO...
eetimes.com
Are We Ready to Give Up Driving?
In a Strategy Analytics survey, 40% of Americans said they...
eetimes.com
Broadcom Cuts 2,500 jobs
Broadcom announced plans to cut 2,500 jobs, 20% of its...
eetimes.com
AMS, Dialog Merger Talks Fail
Talks over a possible merger of mixed-signal chip companies AMS...
eetimes.com
The Risks & Rewards of Early Tapeout
Verification remains a key issue in system-on-chip development. The time...
eetimes.com
Nikola Tesla, Vincent Van Gogh & the Second Renaissance
Tesla was alive at the same time as Vincent! Both...
eetimes.com
Future of PCM: Optoelectronic?
Work by a team at the University of Oxford and...
eetimes.com
Mobile Uptick Ahead, Says ARM
Mobile device shipments are rebounding from a slump, but challenges...
eetimes.com
EEVblog #643 – Mailbag
Mailbag Monday Spoilers: Dual voltage source selection circuit Casio FX-7000G...
eevblog.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +