Questions tagged [powermosfet]

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Help identifying this MOSFET

Trying to figure out what this is, and suitable replacements. Markings are "1 Wt 77" Cannot seem to find anything. Edit: I removed and sized it today, looks like 2.04 mm square package, ...
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2 votes
1 answer
180 views

Replace an N-channel MOSFET with equivalent in chinese solar inverter

I am planning to replace the NCEP85T16 MOSFET in a Easun SV IV hybrid inverter. The blown out MOSFETs are on the 48 V battery DC boost side of the inverter. I found a possible replacement in Toshibas ...
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2 votes
1 answer
72 views

How is MOSFET gate resistor chosen?

I have been doing research on MOSFETS. I see that in a typical circuit that includes a MOSFET and a Driver IC, there is a gate resistor. I have done research on this gate resistor and I am aware that ...
2 votes
0 answers
84 views

How to compute the SOA of a MOSFET?

Is there any tool to check if a MOSFET is within its SOA or not for a given operating condition?
2 votes
0 answers
78 views

Ringing at input of digital isolator while driving a mosfet with high voltage and current

From a rectified main 230V supply + 4x120µF 400V capacitor, I'm driving a STW40N65M2 mosfet which commutes a big coil. Gate is driven by MCP14A0304T. Gate current is limited by a 30.9 Ohm resistor. ...
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2 votes
1 answer
81 views

Mitigating parasitic turn-on of MOSFET

UPDATE Thanks Aaron and jp314 for your comments. We just probed some more and I think jp314 is right. We found that the high side driver was skipping some pulses. The pink pulse train is from the ...
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2 votes
0 answers
252 views

MOSFET Bootstrap circuit simulation with NGSPICE

Preface I am designing a Solid State Relay as an educational exercise, to catch up on what my university did not teach me. I am a long time Linux user and open-source software lover, which brought me ...
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2 votes
2 answers
617 views

H Bridge runs for few minutes and MOSFETS start smoking

I have created an H bridge as shown in the schematic below. PWM signal to the MOSFET driver is given by a microcontroller running on 5V. The MOSFETS are screwed to heat sinks. To control the motor ...
2 votes
0 answers
828 views

MOSFET Driver P-channel

I want to create a DC-chopper to drive a motor. I found the following schematic online: However i don't understand how the MOSFETs are driven. On top there is a P-channel MOSFET with source connected ...
2 votes
0 answers
402 views

Overshoot/undershoot issues in load current wave form of a MOSFET

We have designed hardware circuit which validates voltage regulator maximum output current. So we designed op-amp circuitry to control gate drive of the Power MOSFET and it will work in active region ...
  • 1,273
1 vote
0 answers
23 views

Need help with a DMP3028LSD-13 - PMOS in dual way power path design. Currently, load resistors are needed to turn the path off

I have implemented a bi-directional independent power path using a DMP3028LSD-13 PMOS. When a supply is connected on the A side (power source +5V,) voltage is reflected on the side B (no device/load) ...
1 vote
2 answers
80 views

What is the reason why thermal aging affects only the Cds capacitance but not the Cgs or Cgd capacitances?

Please take a look at the following images, experimentally obtained from a power cycling test of a power MOSFET. After the test where thermal aging is created due to repetitive power cycles, it is ...
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1 vote
0 answers
91 views

P-Channel MOSFET - Vsd unexpectedly high when driven on?

Using this cct with a FQP27P06 P-Channel MOSFET. I am trying to switch 12V power on the high side to a non-inductive load drawing about 3A . I am expecting 0.07 ohms x 3 A = .21V drop across the ...
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1 vote
0 answers
167 views

Revision and component selection of MOSFET driver circuit

I'm developing a board to drive 5 LED strips with 1A maximum current. I need some help for design validation and component selection. The circuit is the following (repeted 5 times). The PWM signals (5 ...
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1 vote
0 answers
121 views

How can I turn off a MOSFET when the temperature rises?

I am using a MOSFET as a pre-regulator. When the voltage is too high, the temperature of the MOSFET is getting too high. (Even if I take 15 mA current.) As a safety precaution, if the junction ...
1 vote
0 answers
76 views

Getting More Power out of an H-Bridge

tl;dr: how to design an h-bridge to give more power to motors. pre-fab circuits are not an option. Hi, so for my electronics class we have to build robots from scratch. So no pre-fab circuits (with ...
1 vote
0 answers
228 views

How to calculate snubber for switched inductor?

I'm driving inductive load with PWM and my MOSFET can not handle hard switching without reduce dv/dt ramp between drain-source. So I need to add RDC (resistor-diode-capacitor) snubber, but I don't ...
1 vote
0 answers
166 views

Calculating MOSFET gate current with \$Q_\text{total} = I_\text{gate} \cdot t\$

Hi I am using the MOSFET IRFP4368. I want to use the equation $$ Q_\text{total} = I_\text{gate} \cdot t $$ to calculate the required gate current of my MOSFET driver. I have my total \$Q_\text{total}...
1 vote
0 answers
973 views

MOSFET activates every time when ESP32 is restarted

I am using ESP32 (GPIO-13) and RFP30N06LE to control my load (Motor). Everything works fine until i restart/reset the board, Motor starts irrespective of state (ON/OFF). I tried adding pull-down but ...
1 vote
1 answer
114 views

Power Mosfet Information Mismatch: On Region Characteristics vs Total Charge Graphs

I'm dealing with Power N-Chanel Mosfets and, while looking at the data sheet of several units, I noticed that the information about the On-Region (\$ I_{D}\$ vs \$ V_{DS}\$) and the Gate Charge (\$ V_{...
1 vote
1 answer
72 views

MOSFET switching seeing unneccessary pulse during Power ON

We have a MOSFET switching circuit to switch secondary(battery 5V) supply to load if power lost on primary(12V). Circuit works fine currently. But i am seeing a LOW pulse on highlighted red net in ...
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1 vote
0 answers
744 views

Electronic load for negative voltage PSU

I am making a MOSFET based electronic load to test my PSU rails. Below is a simplified version of my circuit with V2 as the PSU that is being tested. I want to be able to test negative voltage rails ...
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1 vote
1 answer
458 views

MOSFET testing for short from YouTube repair video

At 23:40 in this YouTube video, the presenter does a p-channel MOSFET test for a short, using his bench power supply on the circuit. From what I understood, he disconnected the charger and with his ...
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1 vote
0 answers
208 views

Rise time and fall time issue in the power MOSFET

In our automated design due to MOSFET obsolete we have changed new MOSFET which gives us rise and fall time issue at the frequency applied from 10Khz to 500Khz. when we use the power MOSFET as Load ...
  • 1,273
1 vote
1 answer
179 views

Calculation of Vce from Ic-Vge Characteristic

We have found the Ic-Vge (collector current vs gate-emitter voltage) characteristic of an IGBT device as shown below at a high Vce (collector-emitter voltage) value (here 20V) from the datasheet (...
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1 vote
0 answers
1k views

Buck converter freewheeling diode short circuit damaging the FET

I have a classic buck converter configuration (http://en.wikipedia.org/wiki/Buck_converter) with IXFK120N65X2 power mosfet used as switch and VS-8ETL06PbF used as freewheeling diode. The input voltage ...
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0 answers
76 views

MOSFET as a switch in battery management system

I am designing a BMS circuit for a 48V battery pack. For the switching mechanism, I thought of using a MOSFET as a switch. I thought I could use an N-channel enhancement MOSFET, but I am having ...
0 votes
0 answers
82 views

Why is the MOSFET not behaving as per standard device characteristic curve?

A MOSFET has 3 modes of operation: 1.Vgs < Vth => Cutoff 2. Vgs > Vth and Vds < Vgs − Vth => linear region The MOSFET operates like a resistor, controlled by the gate voltage relative ...
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67 views

Bandwidth: voltage-source vs. current-source gate drivers

Why do voltage-source gate drivers provide low-to-medium bandwidth that does not work well for wide band gap devices, while current-source gate drivers provide hundreds of MHz of bandwidth?
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0 votes
1 answer
37 views

MOSFET On/Off Switch Power Dissipation

Basic setup: A battery is discharged using some lightbulbs wired in parallel. At various points throughout the discharge cycle, lightbulbs are switched off in order to increase the resistance of the ...
0 votes
0 answers
55 views

MOSFET heats up quickly in High power 14V DC-DC bidirectional charging circuit

I am currently design the following circuit to charge a 14V LifePO4 4 cells battery while running a high power motor at 14V 24A. There are some issues that I am currently facing: Without any diodes ...
0 votes
0 answers
36 views

Automatic multiple switch ON when power is applied

I have made a switch as shown in the schematics to turn ON/OFF 24 loads. When I apply a pulse on the ON-signal the load gets 24 V and when an OFF-signal pulse is applied the 24 V at the load gets ...
0 votes
0 answers
115 views

UCC27211 Gate Driver High Side Output Randomly Turns Off

I am operating a half bridge. The high side gate driver output randomly turns off. I am unable to identify why this may be happening. Attached is an image (Pink: HO, Cyan: HI, Green: LI, Blue: Vgs(LO)....
0 votes
0 answers
67 views

How to use MOSFET?

I'm having trouble understanding MOSFET. There is always a voltage at the drain pin (my case: MOSFET on 5 V, MOSFET off 4.8 V). I've tried n-channel irfz44n and p-channel irf4905, but the result is ...
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79 views

Voltage at the drain of P-channel part of IRF7319

Given the switch schematic: When I applied 5V to VCC and pressed SW1, I measured 4.8V on the drain of Q1B. With SW1 released, I measured 1.85V on the drain of Q1B. I read that power MOSFETs require ...
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0 votes
1 answer
119 views

How should fuses be used for MOSFET temperature protection?

I am using high voltage MOSFET in TO-220 package with a heatsink like this one: Under normal conditions, the temperature of heatsink does not exceed 90 degrees. My MOSFET can run up to 120 degress ...
0 votes
1 answer
62 views

Data Sheet help: Current flowing through a MOSFET module

In a MOSFET module, when looking at the data sheet can I assume the current through each MOSFET device is the given Id, or is Id the current moving through the entire MOSFET module? For the data sheet ...
0 votes
0 answers
68 views

Driver output to FET gate voltage - rise & fall time

I have an ISO driver with the following params: Peak source current = 4 A, Peak sink current = 6 A, Sink resistance = 0.55 ohm, source resistance = 5 ohm. How do I calculate the time between the rise/...
0 votes
1 answer
160 views

push button controlled PMOS high side switch circuit review

I have been working on a project and one of the ideas was to control the power supply by push button. In a normal case, the SW1 is open, the 5v_POWER supplies the 5V_IN; when the SW1 is closed, the ...
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322 views

How to avoid current spike through the MOSFET of push-pull converter at low duty cycle?

I have designed a Push-pull converter as shown: The input is 30V and the output is 400V with the power of 400W. I have designed the MPPT algorithm, magnetic components, etc and the circuit is ...
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0 answers
139 views

I need more information about PowerPAK-SO8 thermal properties than i can find online

There are these MOSFETs in PowerPAK-SO8 (Vishay) package (or SuperSO8 for Infineon). I used to cool them from the outside, attaching a heatsink to the black (plastic? ceramic?) case worked pretty well....
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0 votes
0 answers
209 views

Parallel MOSFET and H-Bridge

I need to control a 12V 100A DC motor and I was thinking of using this circuit, I saw many post and application notes that talk about parallelizing MOSFETs but I did not see any circuit using MOSFET ...
0 votes
0 answers
78 views

Buck converter high side switch GND

In Figure 1, I designed a synchronous buck converter using the IR2110S half bridge gate driver integration. However, when I look at the source-GND measurements of the high side MOSFETs in Figure 2, I ...
0 votes
1 answer
69 views

I don't understand why this circuit works with MOSFET

This circuit works, Vgs = 12V, when IN1 = 0V the circuit lets pass an external current that comes from A and goes out through OUT1, for them to happen the voltage between gate and source must be 12V, ...
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0 answers
35 views

Power MOSFET behaving differently at high Vds

I am trying to switch a circuit continuously by pulsing a power MOSFET(IXTN660N04T4) with a function generator. I have attached my set-up below. IXTH500N04T2 was only used for simulation. Their specs ...
0 votes
1 answer
142 views

Half-bridge gate driver fried, how can I make my design work?

I made a half-bridge following the recommended schematics from the IRS2184 datasheet. However when I powered it, it triggered over-current and got quite hot. Here is are schematic and routing. I ...
0 votes
0 answers
48 views

Boost converter, why the voltage derates when frequency rises?

I am simulating a boost converter in ltspice. vin=3V, vout_bst=12V, ideal inductor, capacitor, diode and voltage source. When I use an ideal switch, raising the frequency doesn't affect the output ...
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36 views

What causes a distortion in the output characteristic at low Vds?

Attached are the output characteristics of two different LDMOS transistors, extracted from TCAD simulation, where Vgs = 3.3V. The output conductance clarifies the distortion more. What are the causes ...
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60 views

MOSFET as a switch: operation region during Rise time

In the below picture, during the time period Tri the drain current Id starts increasing linearly wrt gate voltage Vgs and the voltage Vds is clamped to Vd since the drain current hasn't yet taken up ...
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57 views

What will happen if a MOSFET switch circuit is run without the source?

I have a situation where I have to supply the power to the MOSFET gate drive circuit permanently even when the main switch for source battery is turned off. It is because of the fact that the drive ...