Questions tagged [switching-losses]
The switching-losses tag has no usage guidance.
52
questions
0
votes
0
answers
44
views
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 ...
- 1
0
votes
0
answers
28
views
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?
- 409
1
vote
0
answers
107
views
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 ...
- 77
3
votes
2
answers
278
views
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?
- 349
0
votes
1
answer
78
views
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 ...
- 19
1
vote
1
answer
52
views
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 ...
- 35
0
votes
1
answer
88
views
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 ...
- 349
0
votes
1
answer
93
views
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 ...
- 349
1
vote
2
answers
144
views
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\$...
- 778
0
votes
1
answer
76
views
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 (...
- 133
1
vote
0
answers
131
views
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'...
- 21
1
vote
0
answers
128
views
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 ...
- 11
2
votes
1
answer
73
views
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 ...
- 309
3
votes
0
answers
356
views
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 ...
2
votes
1
answer
73
views
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 ...
0
votes
0
answers
104
views
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 ...
- 11
0
votes
2
answers
163
views
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 ...
- 589
0
votes
2
answers
57
views
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 ...
- 101
0
votes
0
answers
194
views
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 ...
- 1,430
0
votes
0
answers
439
views
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 ...
- 91
0
votes
0
answers
126
views
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 ...
- 133
1
vote
1
answer
279
views
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 ...
- 292
1
vote
0
answers
36
views
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 ...
0
votes
0
answers
379
views
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/...
- 109
0
votes
1
answer
432
views
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 ...
- 83
1
vote
3
answers
3k
views
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 ...
1
vote
1
answer
79
views
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 ...
- 829
5
votes
2
answers
1k
views
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 ...
- 107
1
vote
0
answers
2k
views
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 ...
- 251
1
vote
1
answer
191
views
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 ...
1
vote
1
answer
147
views
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 = ...
- 1,613
0
votes
1
answer
157
views
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) ...
1
vote
2
answers
3k
views
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 ...
- 21
1
vote
4
answers
3k
views
Why are switching losses proportional to switching frequency?
Actually in soft switching converters an increase in frequency increases switching losses?
Can anyone explain why?
- 137
9
votes
4
answers
10k
views
How to increase mosfet switching speed, and decrease switching losses?
I hope this is not a too broad question, but what are the best practices to achieve fast switching on a MOSFET driven by a PWM signal?
My current knowledge tells me I can do two things:
1 - To use ...
- 542
0
votes
1
answer
1k
views
MOSFET inverter switching losses/events - 3-phase motor
To keep this simple, let's focus on one half-bridge which supplies sinusoidal current to the motor. Q1 is the high side MOSFET and Q2 is the low side MOSFET.
SPWM outputs change twice per period - so ...
- 133
0
votes
3
answers
818
views
N-Mosfet switch circuit strange behavior laboratory power supply
I'm dealing with an N-Mosfet switch circuit to control, through PWM, the temperature of a heater resistor. The mosfet is a IRFS7430-7PPBF.
The load is driven at 12V and has a power rating of 80W.
...
- 989
0
votes
1
answer
717
views
switching power loss calculation in sinusoidal pulse width modulation
How do i calculate the switching power loss in sinusoidal pulse width modulation SPWM in a H bridge inverter (4 IGBTs), and precisely is it linearly proportional to the frequency switching or to the ...
- 125
2
votes
2
answers
2k
views
Why does this circuit speedup the switching time and reduce losses?
I am a little confused as to how this circuit works:
According to this website its function is to speedup charge time of the MOSFET as well as reduce losses. How does D1 and Q2 actually work to make ...
- 479
4
votes
1
answer
714
views
MOSFET fast turn-off not enough
I have a PWM bridge driving a higher than 1k load from 200V supply. The simplified, equivalent schematic is this:
The drivers I'm using are slow turn-on/fast turn-off and, in the schematic, it's a 50%...
- 17.7k
3
votes
1
answer
2k
views
PWM motor heating
Every man and his dog are controlling DC motors with PWM. Nowadays microprocessors are popular and offer more flexibility than 555 timers and general mixed signal analog electronic. The song remains ...
- 12.4k
4
votes
1
answer
9k
views
Calculation of diode switching losses
I am an Electrical Engineering student.
I'm in my final year and doing a thesis about soft switching.
I am trying to grasp the calculation of diode switching losses. I'm having the impression that ...
- 175
13
votes
4
answers
51k
views
Difference between High- and Low- side switching of power?
Is there any real difference between high- and low-side switching?
Assume:
Switching is for on/off control of an object (My case RPi)
Base/Gate can be driven to Vcc and GND
- 563
1
vote
1
answer
3k
views
Is there a formula to figure out power loss of a power inverter?
Is there a formula that will give me a ball park idea of how much power I will lose when I run my DC battery bank through a power inverter? Is this something that varies depending on the inverter? ...
- 183
1
vote
2
answers
9k
views
Diode losses in switching power supply
I couldn't find a simple approx formula for calculating diode reverse recovery losses!
I am not doing any rocket science, so I just need an approx formula (not worried much about temperature effects ...
9
votes
2
answers
4k
views
Dual active bridge converter
I'm having issues calculating the power losses associated with the operation of a bidirectional isolated dual active bridge DC/DC converter. The converter is controlled using phase shift modulation (...
- 91
9
votes
2
answers
20k
views
How to determine maximum PWM frequency for transistor (2SK2554)
How can I determine (estimate) maximum reasonable PWM frequency for 2SK2554 transistor?
I found timings in datasheet:
I could estimate frequency from this (and make sure that all these times are 20-...
- 5,732
1
vote
1
answer
21k
views
How to use "Voltage controlled switch" in OrCAD?
In this OrCAD project, I tried to build really basic DC-DC Converter with use of "S" or "SBreak" parts in OrCAD's Analog Library. But, According to analysis (picture below), the blue DC line should ...
- 206
4
votes
2
answers
916
views
synchronous buck ls-FET switching losses and dead time minimization
I'm designing a Synchronous buck converter. I'm having doubts regarding the following:
In the rectifying period of the converter, using a Schottky diode in parallel with the low side MOSFET will ...
- 175
25
votes
3
answers
27k
views
Which has better efficiency: step-up or step-down switching voltage regulator?
I have a Lithium battery pack circuit that converts 4.2V (two 4.2V cells in parallel) to 5V.
Another option is to use a step-down converter from 8.4V (two 4.2V cells in series) to 5V.
Considering ...
- 441