Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [switching-losses]

64 questions
28
votes
3 answers

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 both cited circuits are well implemented, which…
dawid
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15
votes
4 answers

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
Alexander M
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11
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4 answers

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 the lowest possible PWM frequency, because switching…
Marcovecchio
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10
votes
3 answers

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 (PSM.) The converter is shown below. There are 4…
mr313
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9
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2 answers

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 20-50x shorter than my PWM cycle length or something…
Kamil
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8
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1 answer

How to determine BJT switching time

Is there some standard way to get information about BJT (Bipolar Junction Transistor) rise and fall times (the high power ones) ? In essence a IGBT is a BJT being driven by a FET, so there should be some high-power, medium-speed BJT.
Diego C Nascimento
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5
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1 answer

What are the implications of a MOSFET not listing switching losses in the data sheet?

Many MOSFETs do not specify switching losses in their data sheets. Does this imply that the losses are too low to worry about? Too high for the device to be used in a switching application? Variable between units of the same product line? Or does it…
Stephen Collings
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5
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2 answers

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 a battery pack (37V nominal) following a certain…
VoltsAndNuts
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4
votes
2 answers

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 prevent the body diode from conducting, and so it…
mik
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4
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0 answers

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 the Vds(on) and Vds(off) values from? Are…
Richard Escobia
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4
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1 answer

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% duty-rati.,The parasitics modeled here also…
a concerned citizen
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4
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1 answer

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 only the turn-off losses are calculated (which are…
Simon R
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3
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2 answers

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 derating can have on my measurement when I am…
Alison
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3
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1 answer

SEMIKRON: Effect of gate inductance on Eon (Switching losses)

I was reading the AN1403 "Determining Switching Losses of SEMIKRON IGBT modules" from…
Jess
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3
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1 answer

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 temperature your device will dissipate? I am using an…
Trev347
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