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Voltage Mode vs Current Mode Direct Comparison: Transient & Frequency Response
In this video, Dr. Seyed Ali Shirsavar from Biricha Digital compares Voltage Mode control against Current Mode control under varying input voltage conditions.
Two nearly identical asynchronous buck power stages are compared under experimental conditions. The first converter is stabilized using Voltage Mode control, and the second uses Current Mode control.
We then vary the input voltage and demonstrate how the frequency response and transient response of these two popular control strategies behave, discussing the results.
Note: The plant transfer function of a standard Voltage Mode converter (without voltage feedforward) contains our input voltage (Vin) as a variable. This means that our plant gain and therefore our crossover frequency change directly as Vin changes, as we show in this video. This is, of course, undesirable.
The plant transfer function of a Current Mode controller does not "directly" contain Vin. However, there is an "indirect" dependence. The Current Mode transfer function is dependent on the slope of the inductor current, the slope of the compensating ramp, and the duty cycle (as well as other variables). The slope of the inductor current and duty cycle, of course, change with Vin. The slope of the compensating ramp may or may not change with Vin, depending on how it is generated.
However, fortunately, these three variables often change in such a way that the impact of variations in Vin appears minimal on the Current Mode transfer function. This is, of course, serendipity, but it does not mean that we will be lucky all the time, every time.
As always, it is best to measure the transfer function under various input voltages to be sure.
For our workshops on power supply design please visit:
www.biricha.com/workshops
zhlédnutí: 740

Video

Easy to Follow Voltage Mode vs Current Mode vs Voltage Mode + Voltage Feedforward Control Methods
zhlédnutí 4,2KPřed měsícem
When applied to switch mode power supplies, the most common control methods are Voltage Mode Control, Peak Current Mode Control and Voltage Mode Control with Input Voltage Feedforward. In this video, Dr Seyed Ali Shirsavar of Biricha Digital will explain, in his easy to follow way, how these control methods work, what their advantages and disadvantages and which one is most suitable for your ap...
Synchronous, Asynchronous, Diode Emulation! Which Switching Strategy is Best for your Application?
zhlédnutí 2,2KPřed měsícem
There are several popular switching strategies when it comes to switch mode power supplies such as Asynchronous, Synchronous and Synchronous with Diode Emulation. In this video, Dr Seyed Ali Shirsavar from Biricha will explain how these three strategies work based on a Buck topology, what their purpose is, and how to chose the most suitable strategy for your application. A detailed presentation...
MOSFET Gate Drive Resistor Selection - Part 2: Turn Off
zhlédnutí 4,1KPřed měsícem
In this is Part 2 of our mini-series on Power Supply MOSFET Gate Resistors Selection, Dr Seyed Ali Shirsavar of Biricha Digital describes how control to turn off speed of our MOSFET independently of its turn on speed. We show how to design a popular MOSFET turn off circuit, how to select the turn off diode and show some nice experimental results. For resistor selection please see Part 1 of this...
Current Transformer based Current Sense Circuit Design for Current Mode Power Supplies
zhlédnutí 2,5KPřed 2 měsíci
In this video Dr Seyed Ali Shirsavar from Biricha explain the operation of a current sense transformer and how we select the correct one for our power supply. We also discuss "current gain" of our current sense circuit for loop disguises and how incorrectly selected current transformer could cause a flattening of the current sense signal and subharmonic oscillations. As it is customary in our v...
How does an EMC Current Clamp Estimate Radiated Emission?
zhlédnutí 2,1KPřed 6 měsíci
In this video Dr Ali Shirsavar from Biricha Digital explains, in simple terms, how an EMC current works and how we use it to estimate radiated emissions to before going to the EMC test chamber. As it is usual in our videos, there will be a practical demo at the end. In a future video will also show how to use the Transfer Impedance plot to calculate the exact value of our measured currents.
Easy Explanation of Units Used in EMC Measurements (dBm / dBuV )
zhlédnutí 3,6KPřed 8 měsíci
Units used in EMC test and measurement such as dBm, dBuV etc. can be confusing. Using numerical examples, in this video Dr Ali Shirsavar from Biricha Digital explains these units in simple terms shows a practical example using real life measurement. A presentation with all the relevant equations can be downloaded from here: www.biricha.com/psudf-dbm
PSU Design Fundamentals: Experimental Demonstration of Inductor Back EMF
zhlédnutí 2,4KPřed 8 měsíci
In one of our previous videos we explained the action of an inductor in a switch mode power supply. This is the second part of our introductory videos about inductors. In this video, we will demonstrate just how big an inductor back EMF can get even when energised with a tiny battery. By simply breaking the current path of an inductor we light up, albeit momentarily, a 230V lightbulb with a sin...
LISN Construction - What is inside of a LISN and why the DUT sees a 50 ohm impedance only
zhlédnutí 3,2KPřed 8 měsíci
In one of our previous videos, we explained the purpose of using a LISN (Line Impedance Stabilisation Network) and how it functions. In this video we open one up, look inside and see why the load sees 50 ohms only. We then measure the impedance of the LISN in the lab with a Bode100 and show that at high frequencies LISN impedance is indeed 50 ohms. You can download a presentation with more deta...
LISNs Explained in Simple Terms: What Is the Job of a LISN & Why Do We Need it for EMC Testing
zhlédnutí 6KPřed 8 měsíci
A LISN (Line Impedance Stabilisation Network) is by far simpler than its complicated name suggests. In this video, Dr Ali Shirsavar from Biricha Digital explains the purpose of using a LISN, its functions, its circuit and why we have to use one when doing EMC measurements. In the next video we are going to dissect a LISN and see what is inside You can download a presentation with more details f...
When to Use Average Values When to Use RMS Values for Power Calculations
zhlédnutí 4,3KPřed 9 měsíci
In this video, Dr Ali Shirsavar from Biricha Digital explains when we should use Average values and when we should use RMS values in our power calculations and why.
Input Capacitor Selection for Power Supplies (Part 3 - Electrolytics/Bulk)
zhlédnutí 4KPřed 9 měsíci
Input Capacitor Selection for Power Supplies (Part 3 - Electrolytics/Bulk) This is Part 3 of our 3 part video series on Input Capacitor Selection. In this video we will discuss how to calculate the size for our energy storage/bulk electrolytic capacitors including voltage rating and ripple current rating. We will then use REDEXPERT online tool to narrow down our choice down and select a suitabl...
Input Capacitor Selection for Power Supplies (Part 2 - Ceramics)
zhlédnutí 4,2KPřed 9 měsíci
This is Part 2 of our 3 videos about Input Capacitor sizing and selection for switch mode power supplies. In this video we show how to calculate exactly how much ceramic capacitance we need on our input in order to reduce our input voltage ripple to a specified value. In the next part we will do the same for Electrolytics You can download the detailed presentation from www.biricha.com/psudf-inp...
Input Capacitor Selection for Power Supplies (Part 1)
zhlédnutí 8KPřed 9 měsíci
This is Part 1 of our 3 videos about Input Capacitor sizing and selection for switch mode power supplies. In this video we talk about why we need input capacitors, what roles ceramics and electrolytics play and we will show on an oscilloscope, how the noise on our input voltage changes with varying amount of capacitance. In the next 2 videos we will show exactly how to calculate the amount cera...
Impact of MOSFET Gate Resistor on the EMI & Noise Spectrum of a Switch Mode Power Supply
zhlédnutí 10KPřed 10 měsíci
In this video we will demonstrate why slowing down our MOSFET in a switching power supply can help us pass the EMC test. We will change our turn on and turn off times of our FET by changing our Gate Resistor and show its impact on the power supply's noise spectrum on a spectrum analyser Please visit our website below to download the accompanying presentation PDF: www.biricha.com/psudf-mosfet-gate
MOSFET Gate Drive Resistor Selection - Part 1: Turn On
zhlédnutí 25KPřed 10 měsíci
MOSFET Gate Drive Resistor Selection - Part 1: Turn On
Miller Plateau effect within MOSFETs explained - a simple and intuitive approach
zhlédnutí 24KPřed 10 měsíci
Miller Plateau effect within MOSFETs explained - a simple and intuitive approach
Understanding Maximum Power Transfer in less than 3 mins
zhlédnutí 2,4KPřed 10 měsíci
Understanding Maximum Power Transfer in less than 3 mins
PSU Design Fundamentals: Inductor Behaviour in a Switching Power Supply
zhlédnutí 5KPřed rokem
PSU Design Fundamentals: Inductor Behaviour in a Switching Power Supply
Power Supply Noise Issues: Interwinding Capacitance vs Leakage of PSU Transformers
zhlédnutí 7KPřed rokem
Power Supply Noise Issues: Interwinding Capacitance vs Leakage of PSU Transformers
PCB Layout Fundamentals
zhlédnutí 11KPřed 2 lety
PCB Layout Fundamentals
DC bias loss in ceramic capacitors: watch the resonant frequency move in real time!
zhlédnutí 4,7KPřed 2 lety
DC bias loss in ceramic capacitors: watch the resonant frequency move in real time!
Does your PSU have a RHPZ? How to solve this problem
zhlédnutí 4,6KPřed 2 lety
Does your PSU have a RHPZ? How to solve this problem
Mixing ceramic and electrolytic capacitors on the output of power supplies
zhlédnutí 19KPřed 2 lety
Mixing ceramic and electrolytic capacitors on the output of power supplies
RCD Clamp
zhlédnutí 23KPřed 2 lety
RCD Clamp
Snubber Design
zhlédnutí 49KPřed 2 lety
Snubber Design
Transformer Measurements
zhlédnutí 17KPřed 2 lety
Transformer Measurements
Transformer Modelling
zhlédnutí 8KPřed 2 lety
Transformer Modelling
Power Supply Compensator Design without Equations
zhlédnutí 16KPřed 4 lety
Power Supply Compensator Design without Equations
Digital PFC Design with STMicro & Biricha ST-PLD Free design tool
zhlédnutí 4,3KPřed 4 lety
Digital PFC Design with STMicro & Biricha ST-PLD Free design tool

Komentáře

  • @qaisarawan93
    @qaisarawan93 Před 2 dny

    So we need to look at the gate to soyrce vootage and make a oerfect shape like you shown by choosing different gate resistor

  • @cliveradvan3414
    @cliveradvan3414 Před 3 dny

    This excellent presentation helped me to confirm that I did correctly understand this behaviour. 😊

  • @shanmuganathanca245

    Clear info, thank you very much 🙏

  • @russellhltn1396
    @russellhltn1396 Před 7 dny

    There's more to electronic design than how it works when new. I'd like to see the results of aging. That electrolytic is brand new. What's it like after it's aged? I believe the high frequencies tend to cook the electrolytic quicker. The ceramic might help slow the aging of the electo as it will handle some of the harmonics. It will also come on it's own as the ESR of the elecro climbs.

  • @sr-someletronica1312

    👏👏👏👏👏👏👏

  • @user-rx3qi8lv8t
    @user-rx3qi8lv8t Před 11 dny

    Very nice Ali

  • @xinpengyang-dz5rt
    @xinpengyang-dz5rt Před 14 dny

    👍👍👍That's great

  • @biswajit681
    @biswajit681 Před 17 dny

    Please make video on slope compensation

  • @xinpengyang-dz5rt
    @xinpengyang-dz5rt Před 17 dny

    It's useful,I want to have more and more vedios explian how to cauculate the devise

  • @xinpengyang-dz5rt
    @xinpengyang-dz5rt Před 18 dny

    I can't wait to learn the second lession tomorrow!

  • @TB-jl9fr
    @TB-jl9fr Před 19 dny

    Notice this for the first time, but are you at a german company?

  • @aimiliosdraginis3178
    @aimiliosdraginis3178 Před 21 dnem

    worst explanation ever, he proved the formula in the rms case using the formula itself xd!

  • @nishantkumar-jz7hb
    @nishantkumar-jz7hb Před 24 dny

    Hello Sir...I like the way you explain these topics with simplicity......I have a question: How to visualise the common mode noise..when the return is sorted with earth.... Also on the digital circuits of PCB...say a LVTTL clk singal....when normally the return is a DGND plane....how to visualise the common mode and differentiation mode current.... Please give your inputs...

  • @WrittenByMasooma
    @WrittenByMasooma Před 24 dny

    My gate driver circuit burnt. What could be the reason?

  • @edgararturovargastorres3482

    Hello Dr. Shirsavar. Thank you very much for the valuable information. I am wondering how different would the design approach be for a two-stage CMC filter??? I think the equations will change considerably am I right? Any design example / resource that you can share?

  • @sadunnakipoglu9471
    @sadunnakipoglu9471 Před 25 dny

    أشكرك وأقدر مجهودك ، تحياتي لك من تركيا.

  • @ajingolk7716
    @ajingolk7716 Před 26 dny

    Woooow yep guessing 🤦‍♂️ ; Ig = Qg/t(tranistion) once you figure the amount of current apply ohm law R = V/I 🤷🏻‍♂️

  • @stevenbliss989
    @stevenbliss989 Před 26 dny

    I can see that the electrolytic is doing squat, so four 47uF ceramics would be the way to go! :)

  • @nickharrison3748
    @nickharrison3748 Před 27 dny

    dosent the calculation affect fall time

  • @nickharrison3748
    @nickharrison3748 Před 27 dny

    Very nicely explained and demonstrated.

  • @hadihachem8885
    @hadihachem8885 Před 27 dny

    Excellent video and explanations!

  • @prakashom11344
    @prakashom11344 Před 28 dny

    hello Sir how to find transfer Function For Totem Pole Boost PFC. and how to proceed for close loop control.

  • @rahulsingh-iw2yx
    @rahulsingh-iw2yx Před 29 dny

    I am lucky that i came across this explanation. Many thanks!

  • @LapsetoTime
    @LapsetoTime Před měsícem

    ❤️❤️❤️ Nothing better tuen a practice demonstration , Thanku sir

  • @ruhollahyarinejad4622
    @ruhollahyarinejad4622 Před měsícem

    Thank you so much for your teaching. Please introduce a video about the extra capacitor between P and N.

  • @mehmetdurna3115
    @mehmetdurna3115 Před měsícem

    Dear Dr. Shirsavar, many thanks for the video. Due to the real estate problems, what is the negative consequences if we do not balance the inductor over the positive and negative rails?

  • @mehmetdurna3115
    @mehmetdurna3115 Před měsícem

    Dear Dr., many thanks for the video. What is the negative effects if we do not balance the LC filter inductors over the input rails?

  • @serhatdalga7038
    @serhatdalga7038 Před měsícem

    Thank you , It is really very useful.

  • @user-gz1dk2kp8k
    @user-gz1dk2kp8k Před měsícem

    chetta bell and rose watch fake udoo...😁

  • @ChuangChang
    @ChuangChang Před měsícem

    I heard that Current Mode is easier to compensate compared to Voltage Mode, for there is no complex conjugate poles. Is that correct?

  • @peterbulanyi1708
    @peterbulanyi1708 Před měsícem

    Fabulous video. I recommend all your teaching videos, they are such a valuable resource. Thanks for producing and sharing them.

  • @sep1853
    @sep1853 Před měsícem

    I have a question this way the turn off time is always faster than the tun on isn't it?

  • @perrynew8153
    @perrynew8153 Před měsícem

    A pleasure to follow your teachings on all these subtleties and techniques of power electronics. Regarding your series on capacitors, which capacitor technologies would be most appropriate for the creation of compensation networks (error amplifier) of SMPS ? Thank you

    • @joet4348
      @joet4348 Před měsícem

      I'm not the poster, but I believe ceramic caps are pretty common for the PI / compensation amp. They have good capacitance density so they can be quite small. X7R dielectrics are pretty common; they have good capacitance density (lot of capacitance in a small package), usually have a ±10% tolerance but the capacitance has some voltage dependence. C0G dielectrics are also available; they have lower capacitance density but have very little voltage dependence and are available with ±5% tolerance. X7R is usually good if you need a larger capacitance and / or precision is not too important like filtering applications and C0G is generally better for applications where precision is important like setting a precise delay time. There are other ceramic dielectrics available that you can check out if you're curious.

  • @joet4348
    @joet4348 Před měsícem

    Awesome. Thank you for this direct explanation. It helps contextualize the control schemes I've seen and clarifies the advantages and disadvantages.

  • @dwagner6
    @dwagner6 Před měsícem

    Every video is just great! You really have a gift for explaining these things.

  • @justinabrahams9432
    @justinabrahams9432 Před měsícem

    Hi. I have trouble with my halfbridge inverter for induction heating. I get high voltage spikes that i cant seem to get under control, so voltages are building up on the gate of the mosfets. Can you please help or advise?

  • @NoName-gh5zt
    @NoName-gh5zt Před měsícem

    What a beautiful explanation. I cant skip your video. You make learning more interesting. Thank you sir

  • @CLGilbert
    @CLGilbert Před měsícem

    Solid video. Just a few new points. Minimum 2 samples per RBW. This scope has a fixed 751 sample span. Thus, 9000/2 * 751 gives a max span of 3.38MHz. So you can't actually sweep from 1MHz to 30MHz all at once. Also, there is a minimum required sample time of 200s / MHz for the EMI filter. I think sample time is in the sweep menu?

  • @NoName-gh5zt
    @NoName-gh5zt Před měsícem

    Thank you. you are the best teacher.

  • @initiallearnwithme
    @initiallearnwithme Před měsícem

    Useful for me

  • @lakshmananr6431
    @lakshmananr6431 Před měsícem

    Also, this diodes keeps the circuit alive during the dead between two MOSFETs.. Agree?

  • @WilliamAshleyG
    @WilliamAshleyG Před měsícem

    Do electrolytics need to be used to replace electrolytics??? Like if I want to recap electrolyics in a audio mixer or power supply can I use something that will fail clean rather than spilling its guts?

  • @WilliamAshleyOnline
    @WilliamAshleyOnline Před měsícem

    Do electrolytics need to be used to replace electrolytics??? Like if I want to recap electrolyics in a audio mixer or power supply can I use something that will fail clean rather than spilling its guts?

  • @cheeweiho4232
    @cheeweiho4232 Před měsícem

    1) An inductor charges ( positive voltages) and discharge ( negative voltage) with the same direction. 2) A capacitor charges and discharges with opposite directions. During switch off, should the negative voltage/current go with the same direction with the "switch on one", from the load resistor -> the anode of the Free wheeling diode instead of counter clockwise?

  • @esmfamil3929
    @esmfamil3929 Před měsícem

    Nice as always .

  • @TYGAMatt
    @TYGAMatt Před měsícem

    Very informative. Thank you Sir.

  • @farhadsaberi
    @farhadsaberi Před měsícem

    thank you

  • @volodymyrzakolodyazhny7740

    I am every time astonished by the ability of this man to explain things in a simple, short and totally clear way. IDK why this channel doesn't have thousands of subscribers.

  • @lrdisco2005
    @lrdisco2005 Před měsícem

    When I watch these clips, I miss engineering

  • @mateuszlipinski
    @mateuszlipinski Před měsícem

    Everything clear now! Thank you! I wish i had teather like You in the past. 😊