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34 Threads found on edaboard.com: Push Pull Mosfet
To understand about saturation effects, we should know the core type and flux in regular operation. A push-pull transformer without any clamping or snubber might drive the mosfet into avalanche breakdown in regular operation. Inrush current during output capacitor charging will cause respectively higher avalanche energy which might be (...)
BJT are fast if not driven into saturation. In addition mosfet gate driver must provide low impedance push-pull operation, particularly fast gate discharge. That's impossible with your single transistor high side driver circuit. Just helpless.
A common drain mosfet is a source-follower. It has no voltage gain and is extremely difficult to bias because if you make it push-pull the N-channel needs a fairly high input voltage and the P-channel needs a fairly low input voltage. A CD4007 or a CD4069 cannot be made to do what you want and if you use separate mosfets it (...)
An open drain is the drain of a mosfet that has an external load. Then more than one mosfet drain can be connected to a single load. If all mosfets are turned off then one mosfet can control the load. A push-pull output has two transistors, one of them pushes low and the (...)
You have been talking about flyback topology. Please clarify the circuit. Is it actually push-pull?
Hello dear edaboard members ; I'm really tired of getting the same error from proteus :( I have 48 to 12 V dc-dc converter pre-design(not completed to apply in real life) with UC2525 PWM regulator chip. My problem is when i am trying to drive to mosfet gates(IRFZ44N) PWM-A(pin-11) is nearly correct but PWM-B(pin-14) is about to gnd.(some 1V peak
Need a Heavy Duty Buck Converter with Negative Common. Conditions and Ratings: Input: 18 ~ 30V DC Output: 12.5V / 10A Continuous. Run time: 24hrs at 10A. Cooling system: None / Air Cooling. Input and Output Ground is common. N-Channel mosfet. This was the conditions. I tried with push-pull type, Single Inductor Buck (...)
At least this problems: - RCD not working (wrong D4 polarity) - very slow mosfet turn-off due to bad gate driver circuit. Should use push-pull transistor buffer. It's also unclear if the transformer has right winding polarity for flyback operation.
Do you mean that the external diode is not needed? Yes, very clearly. In addition, you can ask if the diode is needed at all. But that's a theoretical question because it's present in any mosfet. The dominant problem of the transformer push-pull converter is overvoltage after switch-off, caused by the transformer leakage inductan
Your circuit has several issues. Worst of all, 35 V gate voltage will immediately kill the mosfet. You need a voltage limiting means for the gate voltage. Secondly, the relative large load resistor R1 will only slowly discharge the gate capacitance. For fast switching a lower resistance or preferably a push-pull driver circuit is (...)
As a first point, it's a completely bad idea to use RCD snubbers for H-bridges, whatever the R and C values are. They are good for single ended or transformer push-pull output stages. In H-bridges, theý cause high peak currents and additional switching losses. Secondly, the ringing is produced by free-wheeling the H-bridge, as already pointed ou
I guess the OP is asking of additional gate-source resistors used with push-pull gate drivers, as suggested by some publications. If so, no RC time constant calculation applies. The gate will be driven most of the time by a low impedance driver, the resistor would be only effective during rising or falling supply voltage in a small voltage range
You didn't yet mention 8051. It has open drain outputs with weak pull-ups instead of regular push-pull outputs. As a simple solution, you can place strong (e.g. 1k) pull-ups. If you also want safe reset behaviour, an inverting driver (like 74HC04) between 8051 and mosfet is suggested.
hai, In CMOS push-pull amplifier, what is the bias current for both PMOS and NMOS? is it same? if the aspect ratio is different, will the same current flow in PMOS nd NMOS ? How to calculate the total current consumption of push-pull amplifier?? Thanks for your response in advance.. plz reply asap..
Turn off time is raised by load capacitance and open circuit impedance. In order to lower Toff, you need an active load or push pull CMOS driver or half bridge type circuit or a narrow pulse on a very low RLoad. Read specs for test conditions where tOFF applies. VGS = 10 V, ID= 40 A Rise time tr ? 300 ? ns Turn-off delay time td(off) ? 5
Use L293D motor driver IC. U can directly give MCU output as input to this and it will drive the motor. U can also use this in push pull mode, configure it as H-Bridge driver. 88138 On the other hand, u can use power mosfet in H bridge configuration for motor on off. And also can provide PWM to mosfets to control the speed
In a DC link inverter, the first stage is a boost stage - designed using a push-pull or full-bridge converter and a ferrite transformer - not a mosfet-inductor based boost converter. So, the boost stage is necessary, unless you're going to use a bulky 50Hz transformer - but in that case, you shouldn't even bother with a second full-bridge (...)
electro13, You must inform what circuit topology is used ( push-pull / Full-Bridge / etc... ). +++
Concerning power mosfets encapsulated in pack case, assemblable w/ screw, can be interconnectable w/ stack metalic plates, properly isolated. It makes easier build the power stage, and also restrict current flow into a confined region. I saw this concept with a pack IGBT set on a 5KW UPS based on push-pull topology, allowing a very (...)
You can measure the primary leakage inductances on your push pull transformer, you can assume the dominant cap will be the mosfet, use a snubber cap 5-10x this value. calculate R from 0.5 x SQRT(L/C), if you have very high leakage and/or reflected energy from the secondary there are other ways to work out the RC based on Ipk at (...)
Hello, Are you working on a push-pull converter with center-tapped transformer? When you are using mosfets, the magnetizing current will find its way through the body diode of the mosfet that was off. Depending on the leakage inductance of your two windings that form the center-tapped primary, you may need a (...)
A single transistor means class A operation. If the load is resistive, the DC bias current causes a dissipation twice the signal power (assuming a sine signal). Is this what you intend? Otherwise, you should think about a push-pull amplifier.
Hi everyone,can anyone please explain to me how the circuit in the above link works?How the mosfet push pull driver works in the circuit?and what is the purpose of putting a capacitor at the gate of the P-channel mosfet.(main concern is to understand how the push pull driver opereate and the (...)
in push pull no need of an gap in ferrite core
Let me to get back to your original question: but due to this spike my mosfets gets too much hot. The conclusion is most likely incorrect. And regarding the suggested snubbers: it also gets heat up... and broken down...... Snubbers are dedicated to absorb energy. So it's basically normal, that they heat up. The
A push-pull driver as discussed in this thread would be better.
Sorry by the question. But, what is a multilevel inverter ? I work with push-pull and full-bridge topology, but this concept ( multilevel ) is new to me. regards. +++
Using a transformer based push-pull topology circuit. +++
Hi people, I tried posting in the Analog Circuit Design but I got no replies :cry: Anyways, I'm trying to design the output stage of a 1 Watt push pull amplifier using dual NPN RF mosfet at 40MHz and a 24 Volt single supply. I'm not using any inductors or transformers. I'm not sure how to bias the mosfet correctly. (...)
Hi people, I'm trying to design a 1 Watt push pull amplifier using dual NPN RF mosfet at 40MHz and a 24 Volt single supply. I'm not using any inductors or transformers. I'm not sure how to bias the mosfet correctly. What type of biasing circuit should I be using ? Since I'm using dual NPN, does this mean I need a phase (...)
Hi any one help me irfp250 push pull configuration what is maximum dc volt use how to calculate?(Vdss-200V - Rds_on 0.085- Id 33A) Regards kicha in a push-pull configuration the voltage across the mosfet in off state is double the power supply. Moreover there are spikes due to the leakage inductance of (...)
sometime i see the ic datasheet show the push-pull port or the open-drain port. What different for this?
SELECT DEVICES. see the application notes. search google for "push pull amplifier" mosfet .pdf look for similar examples. start with
Do you need this for a on-chip design or you use descrete components? Here's what I think could be done for a on-chip design. You have the output of your op-amp. Take it and pass it through: 1) a NMOS source follower - to level-shift it downwards; 2) a PMOS sourse follower - to level shift it upwards; After the sourse followers you have your pu