Power H-bridge

[JCD]

Does anyone know if there are H-bridge IC's with a drain-current higher then 10A?

 

[Hero999]

Easy, build one with MOSFETS rated to >10A.

 

[dknguyen]

I agree...build your own- much likely you will get much better heat dissipation and minimalism which will make it easier to use. However...

there is two I know of from ST Microelectronics:
VNH3SP30
VNH2SP30 (they are almost identical, except this one has lower resistance but it's current sense output is...not as good...for lower currents because of the scaling)

THey are supposed to be able to handle 30A CONTINUOUS, but I suspect some serious heatsinking is required (ie. massive PCB copper areas around the IC).

You can get them from Digikey or wherever or from:
https://www.pololu.com/products/pololu/0705/

WHere they can also come on a PCB already if you wish as a motor control board...

I'd just build my own though.

 

[philba]

there is another reason for building your own with MOSFETs - when (not if) something gets toasted, it's a lot cheaper to replace.

 

[Styx]

That is such an open question?
I build H-bridges where that source 1000A
its all abt what you use

 

[JCD]

The problem is that I don't know how to open the mosfets correct when I make an own h-bridge. Or would you suggest to use a MOSFET driver IC for that?

 

[Styx]

use a MOSFET driver IC for that

search these forums, me and FET gate-drivers are around a bit.
they are important, very important when PWM is used

 

[dknguyen]

I don't think you need a driver IC...just use PMOS for the high-side and NMOS for the low-side. The gate driver is normally for really huge power applications where NMOS is used everywhere and because of the way NMOS switches on and off, you often need a voltage to switch the high-side transistors that is higher than what you can normally provide.

MOSFETs have 3 terminals. Gate (G), Source(S), and Drain(D). A small gate voltage controls the large current flow between source-drain. For NMOS, D is more positive than S. For PMOS, S is more positive than D. For NMOS and PMOS f the voltage at make the voltage at G as close to S as possible to turn it off. To turn it on, make sure the voltage between G and S are high enough.

Now go Google for H-bridges to read more. Come back with a schematic and specific questions and we'll answer them for you.

 

[Styx]

I don't think you need a driver IC...just use PMOS for the high-side and NMOS for the low-side. The gate driver is normally for really huge power applications where NMOS is used everywhere and because of the way NMOS switches on and off, you often need a voltage to switch the high-side transistors that is higher than what you can normally provide.

Not really. Propper gate-drive is always important.
It is important at low-power but high switching freq and at high power low switching freq.

You need to saturate the FET's/IGBT's as fast and as hard as possible.
Some form of gate-drive is needed, be it a full-blown 6W dedicated totem-pole drive, or just another FET to provide a better connection to a rail

 

[philba]

could you guys point to specific schematics on the internet that show this. I can find lots of example but it's not clear to me if they meet the drive criteria.