IGBT Half-bridge Module Help

[Josh15]

Hi,

I am trying to design a PCB using an IGBT Half-bridge module but don't completely know how to connect the pins. I tried uploading images (.jpg and PNG) and the PDF datasheet but it kept giving me an error. The link to the datasheet is below. The schematic is on page 8 and the package drawing is on page 11 if interested. NOTE: Page 11 is listed as page 1 but immediately after page 10 so I called it page 11.

So to be specific, I'm not sure what pins 10 and 12 connect to. I know that pin 12 is electrically connected to pin 5 and 6. And I know pin 10 is electrically connected to pin 7 and 8. It seems like they would have listed them on the same pins on the schematic like they did pins (5,6) and (7,8) if I was supposed to tie them together on the PCB and to nothing else.



http://www.vishay.com/docs/94507/vs-40mt120uhapbf.pdf

Thanks for the help in advance.

Josh

 

[Colin Mitchell]

It depends on what you want to do.

Basically the lower transistor is a common-emitter device and the upper transistor is an emitter-follower.
This means you need to drive the upper transistor from a PNP transistor to turn it on and then you drive the PNP transistor via an NPN transistor.
You need two of these modules to drive a motor in forward and reverse.

 

[Josh15]

I am actually going to parallel three of them to create an inverter. The part that throws me is there are 3 terminals at a single node. What do they go connected to? I can identify all but pins 10 and 12. 10 is on the same node as the negative rail pins and 12 is on the same node as the output but they are listed separate on the datasheet.

 

[Colin Mitchell]

What's an inverter?

 

[Josh15]

To convert DC to AC

 

[Colin Mitchell]

How do you expect to convert DC to AC with this black box ???

 

[Josh15]

Using PWM and gate drivers. O! Hmm, are these both for feedback to the gate driver? I know pin 9 and 11 are for the gates. I'll read some application notes on gate drivers.

 

[hevans1944]

It looks like Vishay brought the gate-control return lines out to separate pins, so you don't get switching currents from the load in the return lines when you drive the gates. So you use pin 10 as the gate drive return lead for the gate driven on pin 9, and pin 12 as the gate drive return lead for the gate driven on pin 11. The load of course is driven from pins 5 and 6, with the positive supply rail connecting to pins 3 and 4, and the negative supply rail (or power ground, if not using a negative supply) connecting to pins 5 and 6. Be careful with the driver design: you don't want to ever turn both IGBTs on at the same time! These are pretty fast devices, 8 kHz to 60 kHz, so a good oscilloscope will be necessary to observe the gate switching waveform transitions. The gate input capacitance is considerable, more than 5000 pF, so the drive current in pins 10 and 12 during switching will be also be considerable to charge and discharge the gate capacitance. Make sure the drivers can provide the current needed at your PWM switching frequency and that circuit inductance in the gate drivers doesn't slow down the gate drive to the point that one gate is turning on while the other gate is turning off. Datasheet says these puppies can be paralleled and will share current reasonably well, probably because the IGBTs have fairly large forward saturation voltages at their rated current. An excellent heat sink is necessary of course.