gate driver IC for tl494

Thread Starter

myil

Joined May 2, 2020
80
Hi,

I would like to design a 12V to 340 V push pull converter with tl494. I would like to know if I need a gate driver IC for power MOSFETs?

Regards
 

Papabravo

Joined Feb 24, 2006
14,407
Hi,

I would like to design a 12V to 340 V push pull converter with tl494. I would like to know if I need a gate driver IC for power MOSFETs?

Regards
I'm not familiar with this terminology. What power levels (In and Out) are we talking about and is there a transformer involved?
 

Papabravo

Joined Feb 24, 2006
14,407
12VDC input, 340VDC and 500W output. Yes, a transformer involved
So for 500 Watts of output power @ 340 VDC you will need, assuming 85% efficiency, about 500 /0.85 ≈ 590 Watts of input power. That means you will need an input supply of 12 V @50 amperes. First of all do you have a 12 V supply with that capability? Second, these are seriously dangerous, possibly lethal, power levels. What kind of experience do you have with such circuits?
 
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Thread Starter

myil

Joined May 2, 2020
80
So for 500 Watts of output power @ 340 VDC you will need, assuming 85% efficiency, about 500 /0.85 ≈ 590 Watts of input power. That means you will need an input supply of 12 V @50 amperes. first of all do you have a 12 V supply with that capability? Second, these are seriously dangerous, possibly lethal, power levels. What kind of experience do you have with such circuits?
It's necessary for my project. I am designing a pure sine wave inverter. I will probably use a car battery.
 

Papabravo

Joined Feb 24, 2006
14,407
It's necessary for my project. I am designing a pure sine wave inverter. I will probably use a car battery.
A 12VDC to 340 VDC converter and a pure sinewave inverter are kind of different things -- don't you think? Why the obfuscation?
What progress have you made so far on this design?
Do you have a schematic?
 

Thread Starter

myil

Joined May 2, 2020
80
A 12VDC to 340 VDC converter and a pure sinewave inverter are kind of different things -- don't you think? Why the obfuscation?
I am going to use 340VDC as a bus voltage. So first, I will boost 12V up to 340V and then I will chop 340V by spwm signals and filter it.
 

Papabravo

Joined Feb 24, 2006
14,407
I am going to use 340VDC as a bus voltage. So first, I will boost 12V up to 340V and then I will chop 340V by spwm signals and filter it.
That voltage ratio is 28.33:1 which means your current ratio on the 340 VDC bus is going to be the reciprocal. I think this is going to be a heavy lift. Do you have a schematic for any part of this yet?
It looks like the UC3843 has a ±1A driver so if you use that chip or a similar one you should not need a separate driver chip, but having said that we still don't have your schematic so we really have no real idea what you are up to. Let us know how designing in a vacuum works out.
 
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Papabravo

Joined Feb 24, 2006
14,407
What is the turns ratio and/or the primary and secondary impedances of the transformer. Are you sure it can get you to 340 Volts on the output?
With practical values for the primary and secondary impedances (turns ratio) I cannot get from the +12 center tap to anything much above 120 VDC.
I also an not familiar with that particular IC, so I can't help with any practical tips.
 
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Papabravo

Joined Feb 24, 2006
14,407
What is the turns ratio and/or the primary and secondary impedances of the transformer. Are you sure it can get you to 340 Volts on the output?
With practical values for the primary and secondary impedances (turns ratio) I cannot get from the +12 center tap to anything much above 120 VDC.
I also am not familiar with that particular IC, but I did look at the drive current and it is limited to 200 mA. That is 20% of the ±1 A drive current of the UC3843
 

Papabravo

Joined Feb 24, 2006
14,407
OK. I was curious enough about how you were going to get there that I did the following simulation. Looks OK except for some predictable losses which you will need to compensate for if you need exactly 340 VDC.
DC12_DC340.png

Enjoy
 

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