Questions tagged [switching-losses]
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68 questions
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Ferrite Core Losses calculate
I want to calculate the losses of a ferrite core. I don't want to rely on TDK limited charts and numbers.
Here Magnetics INC has a calculation with constant numbers which is very useful
I am looking ...
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Three-phase IGBT inverter - Switching Loss Model
I aim to model the switching losses in a three-phase IGBT inverter controlled using Space Vector Modulation (SVM). I intend to use the approximated formula found in this paper, equal to:
$$P_{sw}={1\...
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Why is this example of calculating the switching loss of a MOS transistor with an inductive load considered misleading?
I just saw an example of calculating the switching loss of a MOS transistor with an inductive load from this (page 20). Can anyone explain why they said this is ...
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How can we interpret Cgd in parallel with Cds in the buck circuit?
From this document, it's straightforward to see why Cds is included there because it's in parallel with the high-side switch, and its energy will be dissipated via the Ron of the switch when it's ...
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Push-Pull DC converter - resonance in the waveform
I'm building 48v to 200v Push-Pull DC converter.
And now I'm close to finishing the project, but when I checked the waveform on the transformer I discovered that it looks like this:
(on this picture ...
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Why is an LLC converter designed to operate in the ZVS region? how does the Resonance in the LLC circuit contribute to low "MOSFET losses"?
For the first question I understand that operating in the ZCS region can result in shoot through but why does that happen?
I understand that an LLC converter uses the leakage inductance of the ...
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Reverse recovery diode power loss in switching MOSFET
For designing a low side non-sync buck regulator I am looking for MOSFET(s) that can provide low overall power loss. Conditions would be 60V to 48V, 10A, 600 kHz (worst case), 1 Ohm source and 0.35 ...
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Efficiency curve of synchronous DC-DC controller with external MOSFETs
I'm designing a 48V to 12V, 300W buck converter. I am considering using the LM5148 controller and NTMFSC004N08MC switches. I'm confused about how synchronous DC-DC controllers can list efficiency ...
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Power loss of MOSFET
How can I calculate the power loss of a dpak Mosfet after adding thermal vias around it?
I added a 14x7 matrix of 0.5mm THT vias with in between distance of 1.3mm to relieve the thermal stress around ...
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Measurement with High Voltage Differential Probe
I am doing a measurement with this a 100 MHz high voltage differential probe with voltage derating. As per datasheet of TT-SI 9110 probe, the derating curve looks like below.
What impact this voltage ...
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Thermal Loss calculation of IGBT
I want to compute losses of an IGBT using datasheet information given by manufacturer. I want to calculate losses at 90 °C junction temperature while the information provided on datasheet is only for ...
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In MOSFET switching loss calculation, where does the 0.5 factor come from?
I am going through this material for calculating the switching loss of the mosfet.(https://www.monolithicpower.com/frequency-selection-in-switching-power-supply-designs-part-i)
The switching loss ...
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SEMIKRON: Effect of gate inductance on Eon (Switching losses)
I was reading the AN1403 "Determining Switching Losses of SEMIKRON IGBT modules" from SEMIKRON.
https://www.semikron.com/service-support/downloads/detail/semikron-application-note-...
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How to calculate thermal heat from a switching voltage regulator?
I found this answer here which explains how to calculate the watts that are dissipated in a switching voltage regulator, but once you calculate the watts dissipated how do you know how much ...
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Does body diode reduce MOSFET switching loss in a power converter?
In power converters, it is common that MOSFETs are fed a PWM signal to have cyclic switching. Part of the power is lost in the process. Does the body diode reduce this loss? It seems most power ...
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Custom power source switching
I designed a circuit to switch between battery (+ up converter) and 5 V coming from a cable based on an n-channel and p-channel MOSFET.
Will this work? Will the voltage drop be minor? Under a load, ...
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Why does my resonant converter add more losses?
I am currently designing a DC/DC converter transmitting energy from a solar panel to a load, using a transformer. The model of my circuit can be found on this figure:
To migitate the losses, I have ...
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MOSFET switching loss calculation
I read the "PFC boost converter design guide"
There is an equation that is used to calculate the switching turn-on loss.
Does anyone know how to get that equation?
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Reverse recovery body diode in synchronous buck converter
I am building a synchronous buck converter from 72 V to 4.2 V 2 A. Is there a way to lower the losses of the lowside MOSFET’s body diode? I am using a switching frequency of 300 kHz and with the ...
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Switching loss calculation formula
I read an article talking about the power switching loss formula, and I am curious about one thing.
How to use math to prove the 1/6 and 1/2 in these two waveforms? Could someone give me some idea?
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IGBT Turn-on switching energy loss
I found this formula to calculate \$E_{\text{on}}\$ for an IGBT:
$$E_{\text{on}} = \int\limits_{t_1}^{t_2}p_v(t)\text{ d}t = \int\limits_{t_1}^{t_2}v_{CE}(t) \times i_C(t)\text{ d}t$$
How can I ...
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Is 0.5CossVdc^2 included in Pswitching losses of MOSFET?
This document (page 3) from TI states that switching losses of a High Side (HS) MOSFET (of a Synchronous Buck Converter) are:
Then is states that another part of the mosfet losses are:
which ...
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Power loss calculation question
Recently I am working on power loss calculation, there are two components I need to calculate, the MOSFET and Diode, and I have some questions I would like to ask you.
What's the most accurate ...
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Flyback diode choice
I am curious about how to determine the turn ratio to get the minimum power loss. Assuming n=Np/Ns Vin=380, Vo=40, different turn ratios can get the same output because Vo =VinD/(n(1-D)).
When the n ...
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MOSFET Selection criteria considering conduction losses, switching losses and working frequency
I am trying to choose a suitable MOSFET for my full-bridge resonant converter for wireless power transfer. The circuit topology is something like the following. Specifications: rated power \$-~500 W\$...
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Junction temperature calculation
I have a question regarding the calculation of the junction temperature of MOSFETs and IGBTs.
An estimation is possible with:
$$T_j = P \times R_{th} + T_a$$
Let us assume that the thermal resistance (...
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Can a voltage peak detector circuit detect square wave overshoot voltage?
I'm building a simple inverter with an inductive-capacitive load.
I wonder if I have overshoot voltage like this on my IGBT:
I want to detect this overshoot, but since I don’t have an oscilloscope I'...
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High efficiency pwm current limiter for charging supercap from alkaline battery
I'm designing device which uses two alkaline C-batteries in series as power source, and sends SMS messages using SIM800. On average 1 message per day is sent. Goal is to maximize battery life.
Allowed ...
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How does the buck regulator soft start condition reduce the unwanted voltage drops from high impedance power sources?
I have been studying the functionality of the soft start function. I understood how it will help to reduce the overshoot of the output voltage as well. Here, my intention is to understand the meaning ...
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How to determine Vds(on) and Vds(off) for switching loss calculation?
In the Infineon Application Note, two of the parameters they've used to calculate the switching loss of the MOSFET are Vds(on) and Vds(off).
Is the Vds(off) the blocking voltage?
Where do they obtain ...
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Can a thyristor regain its forward/reverse blocking capability if the current through it is "instantly" brought to zero?
I am imagining a situation where we have several series-connected thyristors, say 10, each that can block a voltage of 100V. So, the ten series-connected thyristors together can block a total voltage ...
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Low efficiency buck converter
I've seen the circuit below on YouTube.
But it has low efficiency and the p-chnnel MOSFET gets hotter as the output & input voltage difference increases (it goes above 100c with heatsink).
I don't ...
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Lower duty cycle less efficient?
Assume you have a DC voltage V, ideal switch (no switching losses) operating at some frequency f and duty cycle ...
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Any advantage in AC-DC or DC-DC with past, large form factor semiconductors?
I want to clarify this question with my real-world example:
Say you have a device which contains some AC-DC converter (or DC-DC) for rather high power specs (10 kW up to 300 kW, not in the same ...
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Eon and Eoff IGBT losses
I have read several documentations about switching losses in IGBT. Most of documents indicates to use Eon and Eoff curves to calcul the switching losses through the IGBT.
Nevertheless, the Eon and ...
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Calculating switching loss of diode - unknown Qrr
I would like to calculate a switching power loss of BY203-20S diode, in following conditions:
Vr = 1600 V,
fsw = 65 kHz
Switching loss of a diode is given by equation:
\$Psw = Vr*fsw*Qrr\$
We can ...
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832
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Turn-on and turn-off switching energy
Is it possible to calculate the turn-on and turn-off energy of SiC-MOSFETs with datasheet parameters? The method with ½ * U * I * tr (or tf) cannot be used here. Let us take the C2M0080120D from Cree ...
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Does supply voltage affects stepper motor driver heat dissipation?
Below is a block diagram of a stepper motor controller with an external mosfet h-bridge that drives one of the stepper's coils. Let's say that the coil has 2ohm DC resistance and 3mh inductance, the ...
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Is zero loss turn-off possible for thyristors?
Consider this very basic circuit:
simulate this circuit – Schematic created using CircuitLab
Don't mind the values - they don't matter, as this question is conceptual.
Imagine that Vcomm is ...
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513
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How to add thermal model on SOAtherm-Nmos block in LTspice
I would like to analyze the junction temperature of a SCT3022AL MOSFET during switching operation on LTspice.
Followint the Spice model and the thermal model of the MOSFET:
https://www.rohm.com/...
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Linear power supply vs SMPS (losses in transformer)
We know that, in a power supply, there are always losses taking place.
If we have a linear power supply, the major source of loss is the core loss in the transformer.
But in an SMPS, where we have a ...
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Baker Clamp application for PNP Transistor
I have an issue related to Baker Clamp application for PNP Transistor. I know how to implement the Baker Clamp for NPN Transistor. However I do not know how to do it for PNP. So could anyone can ...
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How to calculate the switching loss of an OR Gate?
This is the datasheet of the OR gate. Current consumption as per the datasheet is 25 uA. (Electrical Characteristics table - Page 4
Input current Icc = 25 uA).
I am wondering how power consumption ...
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Speeding up turn-on and off with VOM1271 Photovoltaic MOSFET Driver (/optocoupler)
It's my first post here so please do not hesitate to tell me if I'm not doing it right :-)
A bit of context : we need to switch an array of power resistors (1,3kW, 1ohms) in order to test under load ...
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MOSFET switching losses in LTSpice
I've made a simulation of three-phase MOSFET rectifier in LTSpice. I am simulating different conduction angles and calculating efficiency. However, I would like to also take a look at the switching ...
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Problems sharing data on a common uSD between a camera and micro; - Switch (TS3A27518E)
We are having a lot of difficulties sharing a uSD card between two devices (an Atmel micro which uses the SPI, and a camera). We used to do this using relays, and all worked fine, but cards got faster ...
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Strange behaviour while simulating switching loss
I am trying to simulate gate charge profile and switching loss curves of transistor as in the circuit below. I used ideal current source (30uA) for load, clamp diode (piecewise-linear model with ron = ...
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How to replace microswitches with electronic switches in a voltage / resistor ladder circuit
Hello everyone,
I am relocating a pair of transmission control levers to a different location within a car. At present each lever actuates a pair of SPST microswitches (at the same time) ...
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Dynamic and Active Leakage in CMOS
I studied various techniques to reduce the leakage power consumption in CMOS design. Leakage currents can be static and active.
I understand the meaning of static (standby) leakage, but I am ...
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Why are switching losses proportional to switching frequency?
Actually in soft switching converters an increase in frequency increases switching losses?
Can anyone explain why?
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