Homemade Brushless ESC
I am currently working on building a quadcopter with brushless motors. I decided to try to build the ESCs by myself with some MOSFETs. I am using an Uno as the main controller on the receiving end....
View ArticleMosfet amplifiers mismatch effects comparison?
In Mosfet amplifiers we have Rd mismatch effect and gm mismatch effect .Which mismatch has the biggest,most important effect?
View ArticleClik here to view.
Driving LED from two supplies
In my design, I want to drive a LED using two different supplies depending on the control signal for n-mosfet. One of the supply will be disabled at boot-up. P MOS will be used to enable supply for the...
View ArticleClik here to view.
MOSFET resistance
I’m trying to understand how MOSFET resistances work, but I’m seeing a lot of things that don’t always fit together (probably due to my lack of understanding). Specifically the amplifier configurations...
View ArticleClik here to view.
Unexpected results in Multisim
I am in the process of selecting a N channel MOSFET for switching purposes and thus, tried out this simple circuit in Multisim. But it seems that the MOSFET conducts in the cut off mode and remains off...
View ArticleClik here to view.
Is IRFD 014 an appropriate FET for switching an array of (about 40) UV LEDs?
We have an array of UV LEDs. The LEDs are rated at 3.2 V – 3.4 V at 20 mA, and we plan to use a 5 V supply for simplicity. We will be using a dedicated 100 Ω resistor for each LED (the power dissipated...
View ArticleMOSFET threshold voltage and body effect
I’m trying to simulate a common drain amplifier on LTSpice which can be used to shift the input voltage either up or down by the threshold voltage ($V_{IN}+V_{TH}$ or $V_{IN}-V_{TH}$, depending on PMOS...
View ArticleProtect N-MOSFET against short circuit and overload
I’m using an Attiny and I want to connect a PWM pin to a N-Channel MOSFET in order to fade some LEDs, or switch a motor.Four wires are connected to my board: VIN, two GNDs and a OUTPUT GND. Questions:...
View ArticleClik here to view.
Derivation of depletion layer in depletion mode in MOS Structure
First off, please understand my background. I am doing a course in Digital Integrated Circuits and following the book CMOS Digital Integrated Circuits and Design by Kang (3rd Edition). I barely have...
View ArticleClik here to view.
Adding hysteresis to MOSFET used as a switch
I have a low-voltage detection circuit which I use to trigger one of two LEDs (green, and red) that is powered off of a +9V battery cell. As the battery discharges, its output voltage decreases, until...
View ArticleClik here to view.
Please help determining component specs of BQ76930 (BMS IC)
I was wondering if you guys could help me with some questions I have about the BQ76930 schematic (below, also found here: http://www.ti.com/product/bq76930 on page 42). How can I determine what MOSFET...
View ArticleClik here to view.
Simulating a circuit consisting of MOSFETs
When simulating a circuit consisting of mosfets, when can you say that the MOS should be in cut-off, saturation. or linear (triode) region? Specifically a charge pump circuit utilizing PMOS.(refer to...
View ArticleClik here to view.
I guarantee this one will be fun – Need help putting several circuits...
So I did my best to annotate the schematic with what I’m trying to do. Where I’m really running into trouble is past the output of the 555. This is basically a control circuit for a camera’s automatic...
View ArticleActive load using MOSFET
Good evening! I want to create an active load system where I can vary the PWM signal from the microcontroller to the control input of the MOSFET which is attached to a fixed resistive load. I want to...
View ArticleClik here to view.
Advantages of splitting a single NMOS transistor into two
Can anybody explain to me why in the schematic attached below that using two transistors is better than using only one transistor that is larger (longer)? I see that these two transistors are the...
View ArticlePreference of MOS resistor as load in MOS inverter [closed]
Whys is a MOS resistor preferred over diffused resistor as load in design of a MOS inverter?
View ArticleClik here to view.
Flyback converter current flow?
If you look at the flyback converter circuit above, the current only flows in one of the coils at any instant of time. What stops the magnetic field generated by the coil in series with the MOSFET to...
View ArticleClik here to view.
OP amp voltage comparator for an FET
I have a project requiring a switch (I supply 4.8V, the switch stays off. I supply 5V, it turns on.) After some testing and asking several questions, I realized that the MOSFET I was using would not...
View ArticleClik here to view.
Power supply overshooting during power up and power down
My programmable power supply project in progressing slowly and now it’s time to do something with overshooting of linear “postregulator” during power off and power on. Overshooting on step response is...
View ArticleClik here to view.
High speed MOSFET switch noise
So I have PWM signal controlling an N-FET switch at around 20kHz. While it works in theory, in reality it takes longer to switch the MOSFET off. I assume it is because of output capacity parameter? And...
View Article