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UCC21732-Q1: four quadrant H-Bridge with 1.5kV

Part Number: UCC21732-Q1
Other Parts Discussed in Thread: UCC21732, UCC21750, SN6505B

Hello TI-Team,

I'm developing a H-Bridge to produce a 1.5kV 1kHz sinusoidal wave with a maximum current of 5µA. The H-Bridge itself is build out of IGBT's (IHW30N160R5) and the 1.5kV is delivered by a DCDC-converter (GP15). Now the question is if it's possible to use the UCC21732 as a gatedriver for the IGBT's. My first try of the schematic is shown below.

  • Hi,

    You should be able to use UCC21732 in your application. UCC21750 is another option if you prefer to use the DESAT protection rather than overcurrent.

    Do you have any specific concerns regarding the implementation?

    Also, if youare not using AIN pin on the devices, recommend you tie it to COM.

    best

    dimitri

  • Thank's for your immidiate response.

    So this is the simplified schematic for the case that the fullbridge is switched on. Now the question is, how do i have to construe the resistors R1,R2 to limit the voltages between VDD and COM or COM and VEE? And how about the resistors R3..R6 for the hytheresis, do I need them even if I don't want to implement a hystheresis? It's my first time to develope a h-bridge and I'm a little bit confused by the datasheet.

  • Thank's for your immidiate response.

    So this is the simplified schematic for the case that the fullbridge is switched on. Now the question is, how do i have to construe the resistors R1,R2 to limit the voltages between VDD and COM or COM and VEE? And how about the resistors R3..R6 for the hytheresis, do I need them even if I don't want to implement a hystheresis? It's my first time to develope a h-bridge and I'm a little bit confused by the datasheet.

  • Hi,

    Can you check your previous post whether you made mistakes translating it from your main schematic? Please do NOTconnect VDD/VEE pins to the Drain/source of the IGBT like that. Both drivers will not turn on and blow up immediately.

    1, This can 1.5kV across your supply voltage on UCC21732 which will be a spectacular fireworks show.

    Secondly taking a voltage by resistor, You cannot guarantee the stability of the Drain/Source voltages even if they were in the limits because the ICE/IDS will vary. , but thats not the main reason. The main reason is that it will not work or more likely destroy both your drivers.

    For IC2, should never connect COM to the Drain like that, it should be connected to the source of your IGBTs.Your IC2 VDD is left Floating

    You need to generate stable highside and lowside for the gate driver  supply pins by an isolated supply that floats which is reference to COM.

    One way to do this is to use an isolated flyback converter,

    Please see a reference design with UCC21732  which uses flyback converter:

    Another option is to use a push-pull converter Like SN6505b which can be more cost effective (can use smaller xformer), we also have many reference design which use push-pull converters to generate the bias supplies, such as the UCC21732 EVM.

    The upper SN6505b geneates VDD and lower one generates VEE, which is below COM to offer negative drive bias when turning off.

    In your case, for a half-bridge, you could use 4 push-pull converters, 2 for low-side driver, 2 for highside driver.

    I've attached a screen cap of the schematic. These design files are also available now for you to use.

    Can you modify your schematic so that the drivers supplies are not connected directly to the IGBT terminals? I am happy to help with your questions on implementing. And please let me know if you have further questions on this topic. If i've answered all your questions, please let me know by pressing the green button.


    Best,

    Dimitri