78 Threads found on edaboard.com: Mosfet Npn Transistor
P-Channel mosfet seems to be much better option ..
"P-Channel mosfets, the Best Choice for High-Side Switching"
Electronic Elementary Questions :: 27.12.2006 18:23 :: IanP :: Replies: 8 :: Views: 3915
I have discrete buck regulator (12V to 5V) in my design. PWM switching signal is generated from microcontroller. To drive high side mosfet (P/N) i would like to use TPS2818 gate drive IC.
My controller works on 5V. Can i feed this PWM to TPS2818? Can this generate proper drive for high side mosfet?
Analog Circuit Design :: 11.04.2007 00:43 :: niks :: Replies: 5 :: Views: 1601
Use one P-channel mosfet, with Vth about 6-8 volts.
connect its source to 10V, its gate to Vi input and its drain to Vo.
Electronic Elementary Questions :: 21.09.2008 02:18 :: Davood Amerion :: Replies: 10 :: Views: 700
To qoute can be seen in figure 1 that the source metallization connects both the N+ and P implantations, although the operating principle of the mosfet only requires the source to be connected to the N+ zone. However, if it were, this would result in a floating P zone between the
Electronic Elementary Questions :: 25.06.2009 00:49 :: usernam :: Replies: 4 :: Views: 2760
It looks like the voltage that drives the mosfet's gate is to low ..
Digital mosfets (those designed to by driven by low-volt logic) like to be driven from roughly 4-5V, whereas standard mosfet shoud have the U close to 10Vdc ..
Try to add 1kΩ in parallel with , see attached drawing ..
Hobby Circuits and Small Projects Problems :: 11.03.2010 23:55 :: IanP :: Replies: 4 :: Views: 1630
If you want to control 100 v using a logic ciruit. Which would be better mosfet or npn tranisitor?
Electronic Elementary Questions :: 10.06.2010 06:18 :: blaijon :: Replies: 1 :: Views: 1540
High side mosfet Driver
I need to drive a mosfet to generate a constant current source,
the idea is to drive the mosfet in linear region to obtain a set current corresponding to the VOLTAGE Value .
Is this configurat
Analog Circuit Design :: 27.10.2010 07:37 :: themaccabee :: Replies: 5 :: Views: 2809
In this instance it?s better to use PNP (or P-channel mosfet), as all what you need to do is pull the base (or Gate) down to GND via a resistor ..
If you use npn transistor (I don?t know why you have mixed Source and Emitter ? these are pins of two different types of transistors) then you have to ensure that the Base is at (...)
Electronic Elementary Questions :: 05.12.2010 19:40 :: IanP :: Replies: 5 :: Views: 488
the mosfet gate turnon voltage is always in respect to its source terminal. So when the source voltage is at 4.5v and the gate is still at 3.6 it could already start turning on (logic level mosfet too ? ), so you drop the gate voltage to turn it on hard, sure it might not turn off then, no mystery there :smile:
You must level shift the gate
Electronic Elementary Questions :: 04.05.2011 08:13 :: xaccto :: Replies: 2 :: Views: 624
Post your circuit diagram..
How do you drive the High side mosfets?
You may need a high side driver
Robotics and Automatics Forum :: 30.06.2011 04:40 :: nandhu015 :: Replies: 19 :: Views: 1814
i am using PSMN2R0-60ES NXP N-mosfet as switch for 50V supply, i have got 10K resistor from 50V to Gate and npn transistor is making voltage divider with 10K resistor to control switching of Gate voltage. Drain of mosfet is at 50V.
now with out any load connected drop is 3.5 voltage accross drain and source.. (...)
Analog Circuit Design :: 16.12.2011 07:35 :: ahsoopk :: Replies: 3 :: Views: 1769
I have been looking to other people's design and found out that transistor can work as a switch, mosfet can be work as a switch, and opto-isolator can be work as a switch too.
What i want to know is, application wise what are the difference between this 3 components?
Electronic Elementary Questions :: 15.04.2012 02:36 :: maniac84 :: Replies: 8 :: Views: 1826
Just like raw examples of circuit
Hobby Circuits and Small Projects Problems :: 04.05.2012 17:34 :: tpetar :: Replies: 3 :: Views: 759
yes, it was me. I destroyed the Inverter by adapting the on-off switch to a remote on - off switch. I accidently sent 120vac into the on - off switch with a slip of the screwdriver.
I destroyed 1 power mosfet, 2 electrolytic caps exploded and vaporized some traces.
yes the transistor has a hole in it. Cant really tell if it is a 3B or a 3D
Electronic Elementary Questions :: 02.11.2012 20:33 :: sdowney717 :: Replies: 9 :: Views: 456
Hey peoples, i need your help here trying to power up a fan using a FET transistor.
Fan has 3 wire . Red Black Yellow
This is the mosfet im using.
and i also believe there is this component that my supervisor gave me but i can't find the details and the datasheet. i believe i
Analog Circuit Design :: 05.12.2012 21:54 :: InNeedOfHelp :: Replies: 30 :: Views: 635
Will my circuit work for the following goal?: When INPUT_N is HIGH (i.e. micro is not driving it and it is pulled up to 3.3V), VCC pin on device will have 24V. When Microcontroller drives INPUT_N to be LOW, VCC pin is at 0V (so device is off).
Should circuit below work as intended?
Analog Circuit Design :: 17.12.2012 13:44 :: mav1234 :: Replies: 5 :: Views: 231
mosfet is a transistor technology. It is an extention of the field-effect transistor (FET).
As with bipolar transistor, where you have npn and PNP, you can have two kind of FET (P-channel and N-channel).
When creating integrated circuits, using mainly P-channel mosfet (...)
Electronic Elementary Questions :: 23.06.2004 13:32 :: Big Boy :: Replies: 12 :: Views: 18034
Hi fellows !!!!
I need som help bout using mosfet in place of BJT in DC - AC Invertors / UPS Currently am using D313, 2N3055 & som other npn power transistors with 2.5Vbe I tried to use IRFP260 the same way but its not even conducting kindly help me out if it has any different way of operating or any important / basic point.
Waiting for a (...)
Analog Circuit Design :: 22.02.2005 05:07 :: Sikander Khwaja :: Replies: 4 :: Views: 783
we're currently designing a servo controller for these motors that we've started getting made up . The idea is to make a 'servo beater' for robotics applications, retailing at $15 - $20. Basic specs to include a variety of gearboxes (and nominal RPM outputs 40 ~ 250RPM), quadra
Microcontrollers :: 16.12.2005 07:52 :: fastcomponents :: Replies: 3 :: Views: 5703
I guess the ideal transistor is unidirectional (supposed to conduct in one direction)
But in reality, this is not always the case. Consider the use of transistors as switches in power conversion circuits.
If we use a power npn BJT as a controlled switch (current-controlled) it will conduct current from the collector to the emitter bu
Electronic Elementary Questions :: 04.01.2006 05:01 :: electronics_kumar :: Replies: 3 :: Views: 1470
but i need to know what happens if i use "n"region instead of "n+" in the mos transistor.
you will have a bad characterstic mosfet.
and i think it won't agree with current equations.
TeE ThE EdE
Electronic Elementary Questions :: 10.02.2006 09:08 :: tamerakshar :: Replies: 3 :: Views: 1185
What it does, it creates a higher voltage at the collector of the npn transistor than the Vdrive voltage. This ensures thet the Gate of the mosfet, drives it completely on so its on-resistance is the lower and hence the waste in heat produced in the mosfet is the minimum.
Usually the function of Bootstrap is to increase (...)
Electronic Elementary Questions :: 27.09.2006 07:03 :: platonas :: Replies: 4 :: Views: 1116
Identity of transistor mosfet and bipolar unreal !!!
Principles of the work it differs !
Analog IC Design and Layout :: 31.10.2006 07:16 :: Shurik :: Replies: 2 :: Views: 532
Use solid state relay based on photovoltaic element or integrated solid state relay. Look at IR site for details.
If you don't need galvanic isolation use approprated mosfet as switch.
PC Programming and Interfacing :: 08.11.2006 15:36 :: Hero :: Replies: 7 :: Views: 1868
Im getting a little bit confused as to which mosfet I need. I want it to act with the same 'turn' on characteristics as an npn Bi-polar transistor.
E.G High resistance when no voltage is applied to the gate and then a low resistance when a positive voltage is applied to the gate
I thought the correct (...)
Analog Circuit Design :: 24.11.2006 02:04 :: fala :: Replies: 2 :: Views: 396
i would used P-mosfet and N-mosfet rather transistor for driving motor IRFZ44 would and it's complementary will enough to drive your motor
Robotics and Automatics Forum :: 08.06.2007 06:43 :: e_eja :: Replies: 10 :: Views: 2389
the way you have biased the circuit is right only also the mosfet is stable even through temperature changes....
i think you have to be careful in the selection of resistors and caps to be used....
RF, Microwave, Antennas and Optics :: 25.07.2007 09:49 :: A.Anand Srinivasan :: Replies: 9 :: Views: 4299
how we can check a faulty npn & PNP
and faulty N-cahnnel and P-channel
Electronic Elementary Questions :: 26.08.2007 15:27 :: rabel126 :: Replies: 5 :: Views: 4207
A npn transistor with a suitable base resistance should do for a low power motor, if you want to control its current directly with a TTL level PWM signal. I don't see any advantage of a mosfet over a BJT in this kind of application.
Another (and more expensive) approach would be using a driver IC.
Electronic Elementary Questions :: 23.01.2008 10:51 :: s_cihan_tek :: Replies: 3 :: Views: 1043
A BJT is a bipolar transistor in the sense that there are two types of charge carriers in them. In npn trnsistor the primary carrier in the hole and in pnp the electron. In JFET there is only one type of carrier. In n-channel case the carrier is elctron and in p-channel hole. So JFET is unipolar in that sense.
BJT is a current controlled device
Electronic Elementary Questions :: 04.02.2008 04:22 :: subharpe :: Replies: 2 :: Views: 49929
As you know the Base of the bipolar and the Gate of the mosfet transistors should have a definite voltage for them to work, say the Bias voltage. In fact when the switch in your circuit is off, as the npn transistor is also off, the Base of the PNP transistor has no definite voltage and that's called (...)
Analog Circuit Design :: 06.02.2008 13:53 :: naalald :: Replies: 10 :: Views: 772
I scanned in this schematic for you to try.
In your schematic you use two P-Channel mosfet, the complementary action is achieved by means the npn transistor Q3, just to point because into the previous reply you said use two mosfet P&N instead here is two P mosfet.
I think yo
Professional Hardware and Electronics Design :: 14.05.2010 08:47 :: eziggurat :: Replies: 18 :: Views: 5394
A logic level mosfet with sufficient low Ron will have lower voltage drop than darlington transistor.
Electronic Elementary Questions :: 28.07.2008 05:27 :: FvM :: Replies: 2 :: Views: 581
you should connect Vo op amp to totempole circuit that contain 2 transistor after it you should connect tow emitter by resistor to the gate of mosfet toprotect 2 transistor from second break
in totempole a pnp &a npn are conected together from emitter and base colector of pnp to Vcc ,colector of npn to (...)
Electronic Elementary Questions :: 28.06.2009 05:01 :: kamalifard :: Replies: 1 :: Views: 1129
GE1822 doesn't seem to be a valid transistor. Could it be a 2SK1822 - TO220 mosfet? It doesn't sound a likely drive for a TIP31/32 though. A picture may help as it may show a logo.
Service Manuals, Requests, Repair Tips :: 05.03.2010 13:20 :: keith1200rs :: Replies: 7 :: Views: 1113
You have to describe your situation and application in detail. Is it the DC pulse or impulse. Level of the DC? pulse width?
The basics would be to turn on a npn transistor and use this transistor to turn on POWER mosfetS, if you need more power add multiple mosfetets in parallel.
you can see a simple (...)
Hobby Circuits and Small Projects Problems :: 15.09.2010 09:50 :: lunar :: Replies: 5 :: Views: 1226
If you don't want to face issues while driving a switch from a 3.3V logic consider an inverter based on an npn (or N-channel mosfet) followed by P-channel mosfet (or PNP) working as a high-side switch ..
See fig.3 at:
Electronic Elementary Questions :: 28.11.2010 09:05 :: IanP :: Replies: 14 :: Views: 1792
There are many possibilities to be used in this situation.
Normally you keep the GND connection fixed and do control on the power supply line. Circuits are more tolerant to the voltage variation on the power supply compare to GND potential. See some possible configurations using BJT transistors, mosfet-P and a standard SPST 12V relay.
Electronic Elementary Questions :: 04.08.2011 06:08 :: mister_rf :: Replies: 2 :: Views: 805
Your N-channel mosfet is connected wrong
According to diagrame you posted, its true. Source and drain should be switched ie drain conected to +12V and source to ignition coil. Emiter follower and source follower aplication. Fet will drop 2-4 volts so its not good.
Analog Circuit Design :: 01.09.2011 10:06 :: ALERTLINKS :: Replies: 10 :: Views: 2315
Sounds like you are using an unsuitable configuration of the switching transistor. We would usually utilize a PNP transistor (or a Pmosfet, as suggested) to switch a positive supply. Both will allow a very low (e.g. < 50 mV) voltage drop.
Professional Hardware and Electronics Design :: 28.10.2011 10:34 :: FvM :: Replies: 34 :: Views: 1923
why you , don't use a simple totem pole to drive your mosfet?
Power Electronics :: 16.01.2012 17:52 :: goldsmith :: Replies: 5 :: Views: 398
If you're sending continuous pulse at or around 50% duty cycle, then, it is your meter showing you 2.57V (the average voltage), whereas the actual voltage when output=1 is actually 5V. eg. If you're turning RD0 on, waiting 10us, turning RD0 off, waiting 10us, then turning it on again and so on, you have 50% duty cycle and your PIC goes from 0V to 5
Microcontrollers :: 01.02.2012 13:40 :: Tahmid :: Replies: 17 :: Views: 687
how to choose "PNP-npn" mosfet transistors, which operates more than 13.56 MHz and around 3 amp?
what is the right way to look for a transistor with such specific values?
Electromagnetic Design and Simulation :: 09.04.2012 08:35 :: juak :: Replies: 0 :: Views: 353
It is your luck that the string is current regulating in itself .However , be vary since unbalance in currents /voltage drops across each will tend to fuse one and have the compensation provided by the other .
In any case is is advisable to have a mosfet regulator for each LED with 350mA provided to drain..
You can use transistor regulators too wit
Power Electronics :: 23.06.2012 15:04 :: vimalkhanna :: Replies: 12 :: Views: 622
Im trying to build a circuit which can drive a single led at 2amps,as of now im using 3 mosfets connected in parallel to share heat,would be glad if any experienced people can guide me to build a circuit of above mentioned requirements.
with this post i have attached the circuit diagram of driver only taken from instru
Analog Circuit Design :: 08.08.2012 01:10 :: ashokof1988 :: Replies: 2 :: Views: 525
Even if you got the transistor biassing correct, the 1N4007 is not suitable for high frequency rectification, you need a device with faster switching speed.
At first glance, if all you are trying to do is create -18V, why not use an npn transistor (or better still a mosfet) , the same positive rail for the output stage as (...)
Analog Circuit Design :: 10.08.2012 04:21 :: betwixt :: Replies: 4 :: Views: 327
You can have complementary dual transistors (two chips in package) like BC846PN or BC817UPN. transistor arrays with dual polarity (classical part CA3096) are still manufactured for special purpose, but I doubt that they are suitable for your application. Complementary mosfet pairs in a package are quire common.
Analog Circuit Design :: 16.09.2012 05:16 :: FvM :: Replies: 1 :: Views: 203
There are a LOT of ways you can do this; a simple R-C going into a schmitt trigger is one. The output of your schmitt trigger can drive the gate of a mosfet (or the base of a BJT).
Hobby Circuits and Small Projects Problems :: 15.10.2012 07:57 :: barry :: Replies: 5 :: Views: 495
Sorry if this topic was covered already.
I need a transistor (preferentially an npn) for an current source generator. It seems that on the datasheets such VA doesn't appear. Is there a way to calculate it from the other parameters?
I have to choose a npn for a current source with the output impedance in the range of 100 Mohm.
Analog Circuit Design :: 06.11.2012 05:00 :: gianca :: Replies: 1 :: Views: 139
A discrete transistor solution for negative voltage with quite descent performance could be something like this:
By adjusting resistor R7 you can trim the output voltage, but I simulated the circuit, and it gave pretty exactly -15V as it is.
One advantage is, that all components are readily available types and value
Electronic Elementary Questions :: 08.03.2013 16:46 :: ted :: Replies: 9 :: Views: 216