1 / 8

Embedded Systems Transistors

Embedded Systems Transistors. E. B. C. N. P. N. B. NPN. E. Bipolar Transistor. C. C. B. PNP. E. NPN rules: The collector must be more positive than the emitter B-E and B-C behave like diodes B-E forward biased B-C reverse biased Limitations on I C , I B , and V CE

Download Presentation

Embedded Systems Transistors

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Embedded SystemsTransistors

  2. E B C N P N B NPN E Bipolar Transistor C C B PNP E • NPN rules: • The collector must be more positive than the emitter • B-E and B-C behave like diodes • B-E forward biased • B-C reverse biased • Limitations on IC, IB, and VCE • When rules (1)-(3) are obeyed, IC=hFEIB=IB hFE (current gain) ~ 100 iC governed by transistor action

  3. E B N P N small IC large ICE + + Bipolar Transistor C

  4. E B N P N Transistor Action C B C reverse biased forward biased IC=IB E

  5. 10 V lamp 0.1A 10 V C B E 1K Transistor Saturation switch closes: VBE=0.6V IB=9.4V/1K=9.4mA ICE=(IB)=100(9.4) =940mA to get that much current through the lamp VC would have to go significantly below ground, which is illegal by rule #1 “The collector must be more positive than the emitter” the transistor is saturated---only enough IC currentflows through the transistor to keep the collector 0.05 to 0.2 V more positive than the emitter.

  6. Emitter-Follower • VE = VB-0.6V • when Vin > 0.6V • big current/power gain at Vout=Vin-0.6V • impedance buffer Vin Vout

  7. Power Transistors • Darlington pairs • hFE=(hFE)2 • TIP102/106

  8. Push-Pull Amplifier Stages NPN can only “source” current “crossover” distortion PNP can only “sink” current

More Related