PCIM: SiC mosfet driver reference from ADI and Microsemi
- Release on:2017-05-18
“The design provides customers with an isolated dual-gate driver switch for evaluating SiC mosfets in a number of topologies, said Microsemi. This includes modes optimised for half-bridge switching with synchronous dead time protection and asynchronous signal transfer with no protection.”
It can also be configured for concurrent drive to study un-clamped inductive switching (UIS) or double pulse testing, and the board supports changing gate resistor values to accommodate different mosfet characteristics.
According to Microsemi, when comparing the drives of Si devices to those of SiC devices, there are two important differences to consider:
- Slew rate at the output of a SiC half bridge can be much higher than with silicon – easily 35kV/μS. This affects the design of the gate drive signal isolation and EMI mitigation. It creates potential issues with the method of implementation of parts of the system, such as the gate power dc-dc function. The intention of this board is to provide an off-the-shelf test solution which addresses these issues.
- Compared to silicon mosfets, SiC mosfets are normally driven at wider gate voltages – typically from -5 to 20V. Lower positive voltages can be used if the resulting higher Ron is acceptable. Lower negative drive voltages can be used, possibly down to zero.
The reference design is intended for markets including: aerospace (actuation, air conditioning and power distribution), automotive (power-trains, battery chargers, dc-dc converters and energy recovery), defence (power supply and high power motor drive), industrial (photovoltaic inverters, motor drives, welding, un-interruptible power supply, switched-mode power supply and induction heating) and medical (MRI and x-ray power supply).
Analog Devices’ iCoupler technology, used here, has better than 50ns propagation delay with 5ns matching, and common-mode transient immunity of better than 100kV/us. Lifetime working voltages are available up to 1.5kV in a single package.
The design, MSCSICMDD/REF1, can be downloaded here, and bought as a finished board.
Analog Devices collaborates with Microsemi as part of the Accelerate Ecosystem.
See Microsemi (hall 6 booth 318) and Analog Devices hall 6 booth 458 at PCIM in Nuremburg.