Infineon Technologies EVALHBPARALLELGAN Half-Bridge Evaluation Board

Infineon EVALHBPARALLELGANTOBO1 Half-Bridge Evaluation Board enables easy, rapid setup and test of paralleling 600V CoolGaN™ transistors along with the isolated gate driver IC. The generic topology is configurable for boost or buck operation with limited pulse testing, or in continuous full-power operation. Test points provide easy access to connect signals to an oscilloscope for measuring the switching performance of CoolGaN™ transistors in parallel and the gate driver. This Infineon Half-Bridge Evaluation Board saves time for users designing power circuits to evaluate GaN power transistors functioning in a parallel configuration.

The half-bridge circuit board has a single PWM input intended for connection to a 50Ω pulse or signal generator. Board power comes from a single 5V supply input, which powers everything including the isolated gate driver power supplies. Dead-time between the high- and low-side is pre-set to 100ns but is adjustable via trim potentiometers. An external inductor connects to the supplied pluggable terminal block connector. The output and bus voltage can range up to 450V, limited by the capacitor rating. This half-bridge can switch continuous currents of 28A, and peak currents of 70A during hard- or soft-switching. Operating frequency can be up to 1MHz, depending on transistor dissipation (limited to about 13W per device with appropriate heatsink, thermal interface material, and airflow).

Required Equipment

5V power supply capable of 0.5A output current to supply VCC
Bus voltage supply up to 450V_DC with sufficient current to supply the power needed for the test of interest
- For short pulse testing even to maximum current, the current drawn from the bus voltage supply is very small, as the DC bus bulk storage capacitor provides the instantaneous energy
Signal generator to provide the necessary PWM drive command for the half-bridge
- The generator must be capable of driving standard 5V logic levels into a 50Ω terminated load
- Rise and fall time should be in the 5ns range for best timing accuracy/repeatability
1.2mm slotted screwdriver for adjusting the dead-time trim potentiometers R51 and R61
Interconnect cable for PWM input
- The PWM input connector is a 50Ω terminated MMCX coaxial connector
- Assuming the signal source is a conventional BNC connector, the user will need a BNC male to MMCX plug cable or a BNC to MMCX adapter
Oscilloscope for measurement
- Due to the fast transient voltage and current possible with GaN transistors, an oscilloscope with a bandwidth of more than 500MHz is recommended

For measuring high-side gate voltages, a 1GHz isolated probe such as the Tektronix TIVM1 is recommended
- MMCX connectors are provided for this purpose (TP11 and T21 on the backside of the board)
A standard (more than 500MHz) passive probe with the short ground pin can be used to measure either Q3 or Q4 low-side gate voltage on TP31 or TP41, respectively
- The test point reference on the Kelvin source of Q3 or Q4 may have ground bounce compared to the VSW measurement reference due to L di/dt ground bounce
- A hinged snap-on ferrite core on each passive probe cable can help minimize any measurement artifacts due to CM cable shield currents
- The user can also use a 1GHz active differential probe such as the Tektronix TDP1000
- This can further minimize measurement errors/artifacts due to CM ground currents but can be sensitive to coupled dv/dt from the TIVM1 probe snout
Make sure the voltage probe used on TP12 and/or T34 to measure the switch-node voltage is rated appropriately for voltage and bandwidth
- A Tektronix TPP0850 50x high-voltage probe with 800 MHz bandwidth, Tektronix P5100A 100x high-voltage probe with 500MHz bandwidth or PMK1000 100x high-voltage probe with 400MHz are recommended

Board Specifications

Chart - Infineon Technologies EVALHBPARALLELGAN Half-Bridge Evaluation Board

Infineon Power and Sensing Selection Guide

Infineon Technologies EVALHBPARALLELGAN Half-Bridge Evaluation Board

Required Equipment

Board Specifications

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