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.
Hello FvM and Erikl,
Thank you for the responses.
Standard NMOSFET has even a higher leakage-current when being in the off-state and this current increases very fast at temperatures higher than 90 degrees.
When drain and source can be exchanged could my schematic work as I expect.
I did some...
Hello Erikl,
Thank you for taking the time to respond.
The JFET which I am using in my design is the MMBFJ177 from Fairchild. There is also a type from OnSemi (MMBFJ177LT1G) which has drawn the gate in the middle between drain and source. Could this FET be the solution because I than change the...
Hi All,
I have a voltage to current converter with a slope of 1.2195mA/V (so 0.82V will generate 1mA and 0.082V will generate 100uA).
I have created a circuit with which I can select between these 2 currents with a microcontroller.
For this I am using P-channel JFET because of its very low...
Hello,
Can somebody help me to calculate the formule which gives me
gain and phasedifference between V2 and V1 (see attached picture).
Thank you in advance and best regards.
Hello,
I am using a IR4426 mosfet-driver to switch a IRFR3910 mosfet.
The IR4426 mosfet-driver has a Io+/- of 1.5A.
The IRFR3910 mosfet has a Qg of 44nC (Qgs = 6.2nC and Qgd = 21nC).
If I do not use any gate resistor I learned that I can calculate the mosfet-switch-on time by the following...
Thanks a lot for the answer.
Could you maybe explain a little bit more in what situation Vgs could exceed the maximum rating?
Is this also during power-up when all capacitors are not charged yet and have a very low impedance?
I tested the FET-circuit with a 2k2 resistor and a 43V zenerdiode in order to generate a outputvoltage arround 40V with an maximum outputcurrent 250mA at 60V input voltage.
The FET I selected gets destroyed when switching an inputvoltage of 60V to the circuit. When I look in the datasheet I see...
Hello,
The intended voltage is not important for me yet. I just want to learn more about BJT's and FET's.
Please find attached the scaled diagrams. Looks to me that the FET has better load regulation?
Thank you and best regards,
Wamor
Good notice that I used LTSPICE and thank you for the answer.
I did some simulation as you suggested by replacing R3 and R4 by a current source drawing current from 0 to 500mA.
I noticed that the load regulation using a FET was better than when using a BJT. See attached picture. Do you have any...
Hello,
I am experimenting with some simple electronics and have a question.
I build simple linear regulator with a transistor (see attached picture) and it works fine.
Can I replace the NPN transistor with a N-channel FET. I learned that FET's
could be a replacement for transistors. Can I...
Hello Karesh,
Thank you for your response. C142 is not mounted yet. I will do some testing to find the correct value for this cap. Opamp-type is LM8261 from National and is a RtoR input and output-opamp.
I will do the measurements you suggested and let you know.
Hello Waicom,
Thank you for...
Hello,
I am having some problems with a ADC circuit on my PCB.
When I read the ADC samples this gives a very unstable result.
The ADC is connected by an opamp circuit which converts a 0 - 20mA current
to a 0 - 3.6V voltage which is fed into the ADC121S21 from National Semiconductor (see atached...
Hello,
I am looking for a datasheet for the MSD701R from Motorola.
I searched the Internet but no succes yet.
Can anybody help me with this or point me to a place where i can find the datasheet.
Thank you and best regards,
Wamor
short circuit protection
Hello,
In my design I am using an LM321 opamp for outputting max 24V with a current of 22mA. The LM321 is protected against short-circuits but only when not exceeding the maximum power dissipation. Is there a way protect the opamp against exceeding the maximum power...
x5r x7r difference
Hello,
I have a switching Powersupply design and used x7r capacitor.
I need to change the output-voltage to 9V and therefor also the capacitors.
The values i need are only available in x5r-types. Can these x5r capacitors also be used as a replacement for the x7r-ones. I know...
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.
