ch11 - CH 10 Differential Amplifiers 1 Chapter 11 Frequency...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: CH 10 Differential Amplifiers 1 Chapter 11 Frequency Response  11.1 Fundamental Concepts  11.2 High-Frequency Models of Transistors  11.3 Analysis Procedure  11.4 Frequency Response of CE and CS Stages  11.5 Frequency Response of CB and CG Stages  11.6 Frequency Response of Followers  11.7 Frequency Response of Cascode Stage  11.8 Frequency Response of Differential Pairs  11.9 Additional Examples 1 CH 10 Differential Amplifiers 2 Chapter Outline CH 11 Frequency Response 2 CH 10 Differential Amplifiers 3 CH 11 Frequency Response 3 High Frequency Roll-off of Amplifier  As frequency of operation increases, the gain of amplifier decreases. This chapter analyzes this problem. CH 10 Differential Amplifiers 4 Example: Human Voice I  Natural human voice spans a frequency range from 20Hz to 20KHz, however conventional telephone system passes frequencies from 400Hz to 3.5KHz. Therefore phone conversation differs from face-to-face conversation. CH 11 Frequency Response 4 Natural Voice Telephone System CH 10 Differential Amplifiers 5 Example: Human Voice II CH 11 Frequency Response 5 Mouth Recorder Air Mouth Ear Air Skull Path traveled by the human voice to the voice recorder Path traveled by the human voice to the human ear  Since the paths are different, the results will also be different. CH 10 Differential Amplifiers 6 Example: Video Signal  Video signals without sufficient bandwidth become fuzzy as they fail to abruptly change the contrast of pictures from complete white into complete black. CH 11 Frequency Response 6 High Bandwidth Low Bandwidth CH 10 Differential Amplifiers 7 Gain Roll-off: Simple Low-pass Filter  In this simple example, as frequency increases the impedance of C 1 decreases and the voltage divider consists of C 1 and R 1 attenuates V in to a greater extent at the output. CH 11 Frequency Response 7 CH 10 Differential Amplifiers 8 CH 11 Frequency Response 8 Gain Roll-off: Common Source  The capacitive load, C L , is the culprit for gain roll-off since at high frequency, it will “steal” away some signal current and shunt it to ground. 1 || out m in D L V g V R C s         CH 10 Differential Amplifiers 9 CH 11 Frequency Response 9 Frequency Response of the CS Stage  At low frequency, the capacitor is effectively open and the gain is flat. As frequency increases, the capacitor tends to a short and the gain starts to decrease. A special frequency is ω =1/(R D C L ), where the gain drops by 3dB. 1 2 2 2    L D D m in out C R R g V V CH 10 Differential Amplifiers 10 CH 11 Frequency Response 10 Example: Figure of Merit  This metric quantifies a circuit’s gain, bandwidth, and power dissipation. In the bipolar case, low temperature, supply, and load capacitance mark a superior figure of merit....
View Full Document

This note was uploaded on 04/05/2010 for the course EE EE taught by Professor Ee during the Spring '10 term at Korea Advanced Institute of Science and Technology.

Page1 / 74

ch11 - CH 10 Differential Amplifiers 1 Chapter 11 Frequency...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online