Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
please someone explain me physically how iceo(collector current with base open circuited ) flows ..........why it is greater than icbo?please explain physically..........
Sorry, I do not make transistors. Instead I simply select ones that are already made and use them in circuits that I have designed properly.
None of my many transistor circuits had any proplems caused by icbo or iceo.
- - - Updated - - -
I noticed that this OP called p11 has posted many threads about the very basics of transistors. It is like he is reading a book and looking only at the titles of chapters then is asking questions about them.
Remember Walters (aka Billy Mayo, Danny Davis, Castillovanv, Vancastillo, PrescottDan, davewalker, and haroldbrown)? Him and all these aliases have been banned here and on other electronics forums.
Sorry, I do not make transistors. Instead I simply select ones that are already made and use them in circuits that I have designed properly.
None of my many transistor circuits had any proplems caused by icbo or iceo.
- - - Updated - - -
I noticed that this OP called p11 has posted many threads about the very basics of transistors. It is like he is reading a book and looking only at the titles of chapters then is asking questions about them.
Remember Walters (aka Billy Mayo, Danny Davis, Castillovanv, Vancastillo, PrescottDan, davewalker, and haroldbrown)? Him and all these aliases have been banned here and on other electronics forums.
Sir , firstly i am not looking at the title of the chapter only ... i think this forrum is for helping people , none of the above replies are explanatory , does it mean that no one knows proper explanation ?if you know the answer then what goes in explaining .... everwhere it is written what is icbo and iceo and if given explanation then also given numerically in terms of alpha and beta , i have not found any physical explanation ... if you know , then please kindly answer .. and if for asking questions i get banned here , then i would better like to leave it ..
I used 2N3904 and BC547 transistors for thousands of my circuit designs and they work perfectly. Their icbo and iceo are so small that they are not even spec'd on their datasheets. I never leave the base or emitter "open" anyway.
The iceo is listed as 0.3mA (at 25 degrees C) on the datasheet for the TIO31 power transistor but this transistor is used for fairly high currents so the iebo is tiny. but the base of a power transistor is never left open anyway so the iebo will never cause a problem in a circuit.
Did you learn what are alpha and beta of a transistor? I have never used alpha but the wide range of beta of a transistor listed on its datasheet is very important for you to design the circuit (with DC negative feedback) to reduce the effects of the wide range.
Maybe you are reading about the history of old transistors when they were made of germanium instead of modern silicon?
I looked on my Philips 1969 databook at the AC126 germanium transistor and its icbo is a maximum of 800uA when it is at 75 degrees C. Then the base needed a low value resistor to ground or a reverse input bias voltage to reduce it.
I used 2N3904 and BC547 transistors for thousands of my circuit designs and they work perfectly. Their icbo and iceo are so small that they are not even spec'd on their datasheets. I never leave the base or emitter "open" anyway.
The iceo is listed as 0.3mA (at 25 degrees C) on the datasheet for the TIO31 power transistor but this transistor is used for fairly high currents so the iebo is tiny. but the base of a power transistor is never left open anyway so the iebo will never cause a problem in a circuit.
Did you learn what are alpha and beta of a transistor? I have never used alpha but the wide range of beta of a transistor listed on its datasheet is very important for you to design the circuit (with DC negative feedback) to reduce the effects of the wide range.
Maybe you are reading about the history of old transistors when they were made of germanium instead of modern silicon?
I looked on my Philips 1969 databook at the AC126 germanium transistor and its icbo is a maximum of 800uA when it is at 75 degrees C. Then the base needed a low value resistor to ground or a reverse input bias voltage to reduce it.
sir , for practical purpose i dont have any problem.. what i want to know it to have a clear idea about the currrent flow . i studied boylested, malvino. i have understood icbo , i.e leakage current when emitter open.. i have understood , how it flows , why it flows and all. but for iceo, i.e leakage current when base open ,i have doubts.. i just want to know, how this leakage current flows, i mean which charge particles contribute thix current and why ? i again want to know why iceo is > icbo with physical explanation .everywhere the mathematical clarafication is given but i want answer with physics.
When the base is disconnected (in a circuit it should never be disconnected) then the beta (hFE) of the transistor amplifies the collector to base leakage current and causes an increased current in the collector to emitter. It happens and I do not care about which charged particles cause it.
On another thread you said a backwards description about beta. Do you now understand that beta amplifies base current then the collector to emitter current is much more? icbo is also base current.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
