DIY IGBT Hybrid Gate Driver

Hybrid Driver Plans

How to build and use an RF-HD2 dual hybrid gate driver for IGBT modules from scratch, a kit, or pre-built purchase.

Table of Contents

  1. Recommended Tools & Supplies
  2. Component Identification
    1. BOM Check List
  3. Voltage Configuration Options
  4. Output Current Limit
  5. PCB Stuffing
  6. Soldering
  7. Clean up
  8. Assembly Time-laps Video
  9. Use and Testing
  10. References & Datasheets

About RF-HD2

The RF-HD2 Hybrid Driver is a dual channel gate drive circuit for high power IGBT modules. The RF-HD2 utilizes Powerex hybrid gate drivers and DC to DC converters to provide efficient switching of modules rated up to 400A. The hybrid gate drivers include high-speed optocouplers for control signal isolation and desaturation detection to protect the IGBT from short circuit conditions. Each hybrid DC to DC converter provides fully isolated control power for each driving channel. The RF-HD2 also provides an isolated fault feedback signal.


  • 5A peak output current at 20KHz (higher frequency results in a lower peak output)
  • 2500VRMS isolation for control power and signals
  • Standard AMP MTA .100” input connector
  • Operates on one 5 VDC and one 12-18 VDC supply
  • Wide output voltage swing +15V/-8V
  • Compact Size 3” x 2” (76mm x 50mm)
  • Can be soldered directly to an IGBT module

Component Identification

Bill of Materials / Install Check List

CompletePart IDValuePackage
D1MUR1100E or 0 ohm0.4 Axial
D2MUR1100E0.4 Axial
D3MUR1100E or 0 ohm0.4 Axial
D4MUR1100E0.4 Axial
DZ11N47450.4 Axial
DZ21N47450.4 Axial
DZ41N47450.4 Axial
DZ51N47450.4 Axial
DZ31N47510.4 Axial
DZ61N47510.4 Axial
R14.7K ohm0.4 Axial
R24.7K ohm0.4 Axial
R34.7K ohm0.4 Axial
RG13 ohm0.5 Axial
RG23 ohm0.5 Axial
C182uFE2,5-7 Polar
C282uFE2,5-7 Polar
C582uFE2,5-7 Polar
C682uFE2,5-7 Polar
C4150uFE5-8,5 Polar
C7150uFE5-8,5 Polar
C310uFE2-5 Polar
CN21/4” Ring Lug on 2” WireCustom

Voltage Configuration Options

Collector voltage detection of each IGBT is performed through the series connected high voltage blocking diodes (D1 – D2) and (D3 – D4). The combined blocking voltage of the series connected diodes must be equal to or greater than the VCES rating of the IGBT. For applications using lower voltage IGBT modules, it is possible to use a single detection diode in each channel.

Summary: If the VCES rating of your IGBT or input bus voltage is below 1000V then replace D1 and D3 with 0-ohm jumpers. The ReactorForge is currently using 600V IGBT modules.

Output Current Limit

When using this type of hybrid gate driver, gate resistance RG must be selected such that the output current rating of the driver IOP is not exceeded. The rated peak output current of the M57962L is 5 Amperes.

V = total voltage input to the M57962L
IOP = rated peak output current of the M57962L


24/5 = 5-ohms

Additional Considerations

Large IGBT modules that contain parallel chips have internal gate resistors that balance the gate drive and prevent internal oscillations.  This fact, along with parasitic inductance in the drive circuit and the switching speed of the hybrid driver can result in practical values of RG below the calculated minimum.

In testing, 3-ohms has shown acceptable results when operating at 40-90Khz driving an MG150Q2YS40 N-Channel IGBT in the ReactorForge test unit.

PCB Stuffing

Start with the lowest profile components. If you started with taller components it would be more difficult to get between them to mount the shorter ones. This method also helps with soldering if you are not using a cut and crimp too. You can flip the PCB over between installing the different height components and solder them, pressing down on the PCB hold everything in place.

Axial Components

These include diodes, resistor, and jumpers. All axial components except RG1 & RG2 have a package size of 0.4 meaning the holes to insert the component into are spaced 0.4 inches apart or about 1cm. RG1 & RG2 are 0.5 or about 1.27cm. The gate resistors are 0.5 because in some cases they may require a higher power rating resulting in larger physical sizes.

If you are building this for use in the ReactorForge, you will have two MUR1100E diodes left over (see Voltage Configuration Options).

Solder each axial component before moving onto the radial components. See the soldering section for tips.

Radial Components

These include all of the capacitors. You may also mount CN1 at this point as well or wait and do it last as it is on the edge of the PCB and not obstructed.

Bend or cut and crimp the leads of each capacitor in the same manner as you did with the axial components.

Solder each radial component before moving onto the ICs. See the soldering section for tips.

Integrated Components (ICs)


Tips, Tricks, & Safety

  • Safety
    • A soldering iron can heat to around 400°C, which can burn you or start a fire, so use it carefully.
    • Work in a well-ventilated area and use a smoke absorber.
    • Solder usually contains lead, which is a poisonous metal. Wash your hands after using solder.
    • Never put the soldering iron down on your workbench, place it in the provided holder when not in use.
  • Tips & Tricks
    • Ensure the iron is in its stand and let it heat up for a few minutes before use.
    • Have a damp sponge and a steelwool cleaner on hand. A clean iron tip is essential to form neat joints.
    • Use a tinning compound to ensure your iron’s tip is shiny and clean. You can also melt a small amount of solder on the tip to “wet” it in preparation for soldering.
    • Replace your iron’s tip if it is black and pitted.
    • Hold the iron at an angle such that it contacts the pad and the lead being soldered for a second or two. Both parts need to be hot to form a reliable electrical and mechanical connection.
    • Slowly feed solder at the point where the lead meets the pad, opposite of the iron. Do not apply the solder directly to the iron tip.
    • Keep the iron on the joint until capillary action pulls the solder into the hole. If the joint was well heated and the solder is of good quality, this may happen instantly.
    • Do not apply more solder than is needed to form a uniform and neat connection between the pad and lead. The joint should form a “volcano” shape.
    • If you see a “bubble” of solder and no visible lead, you likely applied too much. Clean your tip off and use it to wick away some of the excesses.
  • Additional Info
    • Do not leave the iron on the joint connection to long. Doing so can damage the component or the PCB.
    • Do not move the component or the PCB before the solder has cooled. Doing so can sling molten solder which can cause burns or shorts on your PCB.
    • Soldering a connection should at maximum no more than about 3 seconds. If it is taking longer your iron may be too cold, the tip may be defective or loose, or your technique may be incorrect.
    • If you have excessive spatter marks your solder may contain to much rosin or is too large a diameter.

Clean up

If your soldering job is neat, your PCB may require little or no cleanup. A quick scrub with a dry, stiff bristled brush can be sufficient to ensure there are no loose solder blobs.

If you have a lot of shiny, sticky residue on your PCB (ideally you should not), clean it with a mixture of Denatured Alcohol, 1-5% acetone, and a soft bristled brush. Too much acetone can dull the surface finish of the PCB but will not damage it.

Thoroughly dry the board and all components before applying power.

Assembly Time-laps

Use and Testing

See the image below for RF-HD2 connection information.

I am working on a test setup to further demonstrate the RF-HD2.

Hybrid Driver Connections

References & Datasheets