Which is preferable as High Side Mosfet/Igbt driver?

[tAhm1D]

Hi all,
Modern Power Electronics is based on efficient use of Mosfet,Igbt,power Transformer,Thyristors etc. Due to inherent drawback, use of power transistor and Thyristor has diminished and mostly now a days Mosfet and Igbt are used. But driving Mosfet and Igbt in all circuits/topologies is not an easy task, especially when High Side and Low Side drive is required. For that reason, different types of driving techniques are used-mentioned below.

a. High/High-Low side driver ic- like IR2110/2113 and numerous other Ics. Those are good but application technique is complex and costly and modern micro controllers can not drive those directly in most cases and optocoupler based ones like TLP 250 cannot be used greater than 25khz.

b. Discreet Driver is cheaper, but for higher frequency its use is difficult and not very reliable in all cases.

c. Many use Gate Driving Pulse Transformer. But its construction is very difficult as it requires core with stringent quality, which may not be available all 
   the time  and hence efficiency is not satisfactory, which generally causes damage of the Mosfet/Igbt itself.

So, what should be the best use or best alternative? Hope to get good suggestions from you all.

[king]

Hi!
  I think the use of gate driver IC's is not bad idea and MGD's like IR2110 or IR2104 or IR2109 are not complicated to operate you just have to provide them PWM signal (e.g 20KHz) using micro controller or by another mean, and as far as optocoupler concerned than they are easily available in the market or also you can by-pass them for first time practice and if you need any circuit in which MGD IC's are used then i will provide you the schematic for your guidance.

[tAhm1D]

Hi,
It is easier to drive high side MOSFET with discreet driver when frequency is low but the discreet driver circuit for high side MOSFET driver for high voltage (300V and up), high frequency (greater than 50kHz) is difficult to formulate. Does anyone have any idea regarding that sort of high frequency discreet driver circuit?

[jzaghal]

Hi,

I suggest you use a pulse transformer. Google "Tesla Coils" for D.I.Y pulse transformer.

Tried it ,good efficient and cheap.

Cheers.

[tAhm1D]

Hi,
Yes lot of things regarding pulse transformer can be obtained from google and it is often said that it is good and efficient- then what? Construction of it and getting proper signal from it is not easy. Have you tried it by constructing yourself- not using ready made one? I tried lot basing on the application notes of different companies but those did not work. Can you please spell out regarding the core,winding etc. in detail? Ready made ones are not available here. This is regarding high voltage and high frequency application.

[localcrack]

Use TC4469 for mosfet drive

[tAhm1D]

Hi localcrack,
TC4469 is an h-bridge driver for p-channel/n-channel mosfet driver, ie. p-channel as high side and n-channel as low side. But for N-Channel mosfet as high side, this driver can not be used. Since, in high voltage p-channel power mosfet is not available, normally N-channel mosfets are used in full bridge/half-bridge. And hence, this driver can not be used for high power application where all N-channel mosfets are used. Moreover, this can not be used for driving p-channel mosfets higher than 20v as it does not include level shifting for the p-channel high side fet, thus this needs to be externally provided.
So, this driver can actually be used as low-side driver.
Normally I use IR2110/IR2113. But the good ones made by IR are costly(much more expensive than discrete drivers). Chinese ones are cheaper but you can not rely on them as they will create 100s of problems in the circuit.
Discrete drivers are better, but I am in search of high-frequency high-voltage discrete drivers for high-side MOSFET drive.

[sohel]

here one design which fully isolated with pt.but didnt tryed yet.

[qolpa]

i used TLP250 before, it was ok but my freq was 20kHz. once in a time i heard about ISL6615 but i never tried it. have a look at it.

[sohel]

i used TLP250 before, it was ok but my freq was 20kHz. once in a time i heard about ISL6615 but i never tried it. have a look at it.

can u share ur hardware design

thanks

[tAhm1D]

i used TLP250 before, it was ok but my freq was 20kHz. once in a time i heard about ISL6615 but i never tried it. have a look at it.

Your circuit probably was of low voltage(<35v) because TLP250 can not be used as high side MOSFET driver in a circuit which consists greater than 35v.
You cannot use ISL6615 for h-bridge operating at greater than 13.2v(as stated in the datasheet).
So TLP250 and ISL6615 are inappropriate for high voltage high frequency high-side driving.

[Ichan]

Fairchild semiconductor high voltage gate driver ic are much cheaper than International Rectifier driver, look at FAN7xxx family.

-ichan

[qolpa]

Your circuit probably was of low voltage(<35v) because TLP250 can not be used as high side MOSFET driver in a circuit which consists greater than 35v.
You cannot use ISL6615 for h-bridge operating at greater than 13.2v(as stated in the datasheet).
So TLP250 and ISL6615 are inappropriate for high voltage high frequency high-side driving.

yes, mine was a low voltage application.

[tAhm1D]

Fairchild semiconductor high voltage gate driver ic are much cheaper than International Rectifier driver, look at FAN7xxx family.

-ichan

FAN Series are not available here. IR2110/2113 are good for both high and low side drive but Microcontroller can not drive it directly and for that additional arrangement has to made. It would be better if any optocoupler based high side driver for high voltage and high frequency should be there, so that it can be driven directly  by microcontroller. I could not find any. Is there any?

[samud]

there are several ways to drive high side mosfet or igbts. u can use pulse transformer to drive highside mosfet. or u can use ir2118 or ir2110. u have to use optocoupler to drive ir2110 or ir 2118. using optocoupler u can get isolation and logic level for drive them from microcontroller. i use last technic to drive 200 volts 1.5 kw pmdc motor  from microcontroller.

[tAhm1D]

Hi,
Which optocoupler have you used? Most of the optocouplers can not be used in high frequency as they have high rise and fall times. I am talking about high frequency (greater than 50khz). Probably your circuit is of low frequency. For low frequency,any optocoupler can be used for driving any load in combination with microcontroller and driver ic as you have mentioned.

[sohel]

R u talking like that?

[HackerNo.1]

Hi sohel,
Good picture. But what does it indicate? I also think most of the optocouplers are slow other than one or two. Is this circuit operates in HIgh Frequency? Can it be operated in the range of 50khz range? If so, what is the frequency and which optocouplers are used? Please tell us so that we can learn from you. Here optocoupler is used for interface only.

Hi Tahmid,
I think discreet driver and optocoupler based driver are not available for high frequency drive. It is better to use Mosfet gate driver Ic like IR2113 or L6386 can be used for high frequency and high side drive. Interfacing with microcontroller can be done like the picture given by Sohel if the rise and fall time of those optocouplers cope up with the microcontroller in high frequency. Let us hear from Sohel what the picture says.

[sohel]

why u want to switching  at  > 50khz pwm? 
look at
http://www.edaboard.com/ftopic354456.html

[HackerNo.1]

Hi Sohel,
I wanted to know from you since the schematic is posted by you. However,if you are not clear regarding your writings and just copied the schematic from somewhere, it is not wise because we undergo the posts here to learn something, not just copy something blindly. I don't want anything. It is just a discussion regarding high voltage and highfrequency switching. However, while I make some smps, I use 140khz freq , which becomes 70khz in each phase in push pull topology normally. However, the example one in http://www.edaboard.com/ftopic354456.html is a failure example,where igbts are burned and circuit was an utter failure. Should we follow the failure case?

[sohel]

R u talking like that?

I AM NOT BLIND, I HAVE TOLD "LIKE THAT" SO HA HAH

[tAhm1D]

Hi HackerNo.1,
In your High frequency application probably you use high low side driver. I am in search of a discreet driver circuit for using in high frequency and high voltage application. It will be used in single phase.Can you put some light on that?

[Ichan]

If you are looking for high speed optocoupler then maybe 6N137 will fit the requirement.

It is more common to use gate driver IC for high voltage section and optocoupler on logic level isolation.

-ichan

[tAhm1D]

Hi Ichan,
Useful information. Your cooperation is appreciatable. I will study in detail.

[myheadhurts]

theres a floating discrete high side driver here..
http://www.innovatia.com/Design_Center/High-Side%20Drivers.htm

Ive built it and it works...although you'll have to tweak it for your requirements ..
I mainly use the st L6386 and the other variations and have had no headaches when using them.

Rob