LT1158 gate driver for a current bidirectional converter

[divanadz]

Hello All,

I'm building a boost inverter circuit and I've decided to use the LT1158 gate driver because it has a built in shoot through protection. I'm using a sinusoidal pulse width modulation control scheme for the circuit. I'm having issues getting a sine wave on the output of my converter when I build the circuit using a the boost inverter configuration. Based on the application note it seems like this gate drive only works for hbridges and synchronous buck converters but I would assume that shouldn't be the case since the boost inverter is a combination of two half bridge converters

boost inverter
https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5941678
lt1158 mosfet drivr
https://www.linear.com/product/LT1158

 

[ronsimpson]

Please attach your schematic. There is far too little information.

 

[divanadz]

Attached is the boost inverter circuit

 

[jpanhalt]

<snip>

Based on the application note it seems like this gate drive only works for hbridges and synchronous buck converters but I would assume that shouldn't be the case since the boost inverter is a combination of two half bridge converters

It works fine with half bridges, as shown in the datasheet:

In fact, I have used the LT1158 in a half-bridge motor controller.

John

 

[divanadz]

Yes, but my configuration is a bit different. The data sheet shows the source providing power to the top mosfet and the load connected between the mosfets. For the boost inverter that I'm trying to simulate the voltage source and an inductor is connected between the two mosftet forming a bidirectional converter with a capacitor connected at the top mosfet to ground.

 

[jpanhalt]

Maybe it would have helped, if you had posted your circuit?

John

 

[divanadz]

I did post the circuit. But here it as again.

 

[divanadz]

I posted the ltspice boost inverter circuit, lt1158 data sheet and boost inverter paper in my previous posts

 

[ronsimpson]

You must be trying to make a sync. boost. Why?
----edited----
I thought this will be easy. So went back to Linear's test circuit for the IC and I can't get it to run. How strange.

 

[divanadz]

Hello ronsimpson.

Well the boost inverter is comprised oftwo current bidirectional boost converters. The boost inverter circuit is in the link below.

https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5941678

 

[ronsimpson]

I dropped my IEEE membership so I can not see it.

Linear has a test circuit to prove the IC works. I can't get the test circuit to work. (in LTSpice)
If the test circuit does not work then how can anything work?

 

[divanadz]

Okay I'll test the circuit. I've attached a pdf circuit instead of the link.

 

[ChrisP58]

It would be more useful if you posted the actual LTspice asc file, instead of just the picture. That way others can run it and probably be able to solve your problem much more quickly.

 

[divanadz]

Okay. Attached is the circuit

 

[ronv]

Okay. Attached is the circuit

You need to drive the driver with a square wave signal like this:

 

[ChrisP58]

Yes, like ronv said. You hit the gate drivers, and ultimately the mosfets, with square waves, turning them fully on and off. You adjust the duty cycle of the square wave constantly to create your sine wave when the on/off pulses are filtered by the LC in the final stage.

 

[divanadz]

Yes the above waveform is SPWM with unipolar modulation. That's what was implemented.

 

[ChrisP58]

Yes the above waveform is SPWM with unipolar modulation. That's what was implemented.

The signal at the input of U1, labeled P1, is a sine wave.