Isolated Gate Driver Adds Miles to EV Range

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When it comes to electric vehicles, range anxiety is one of the reasons that the technology has not been adopted more quickly. Battery technologies have improved enough that the potential mileage of which EVs are capable has risen considerably, but consumers still want more. Optimising areas other than the battery can help. The more efficient the system is, the less energy wasted, which in turn means a longer range. That applies right through the EV powertrain. The weight of components can also have an effect on the range of the vehicle. Some components can have a small effect on mileage, while others can have a more considerable effect.

For example, at PCIM, Texas Instruments launched a single component that the company claims has the potential to extend the range of the vehicle by up to 7 miles each charge. That distance may not seem like much, but it comes from a single component, and over the course of a year, this could lead to an extended range of 1,000 miles for drivers that charge three times per week.

The component is a configurable, isolated and adjustable slew-rate gate driver for high power SiC MOSFETs and IGBTs. The UCC5880-Q1 device is intended for the design of safer, more efficient traction inverters for EV powertrains by increasing power density and reducing design complexity through the integration of a variety of advanced features, including real-time variable gate-drive strength, SPI interface, advanced SiC monitoring and protection, and diagnostics for functional safety.

Achieving an increase in efficiency for traction inverters is difficult as the majority already operate at 90% efficiency or higher. The UCC5880-Q1 gate driver provides the ability to vary the gate-drive strength in real time, in steps between 20 A and 5 A, to improve system efficiency by up to 2% through the minimization of SiC switching losses. This allows the driver to be tailored to the exact operating profile of whatever SiC MOSFET or IGBT that is chosen.

The device includes many protections, such as shunt resistor based over-current, overtemperature (PTC, NTC, or diode), and DESAT detection, including selectable soft turn-off or two level soft turn-off during these faults. The UCC5880-Q1 also integrates an active Miller clamp, and an active gate pull-down while unpowered. An integrated 10-bit ADC is included to monitor up to 2 analog inputs, VCC2, DESAT, and the gate driver temperature for enhanced system management. Diagnostics and detection functions are integrated to simplify the design of ASIL compliant systems. The parameters and thresholds for these features are configurable using the SPI interface, allowing the device to be used with nearly any SiC MOSFET or IGBT.

A SiC EV Traction Inverter Reference Design is available to further cut down component numbers and enable quick prototyping. The customizable, tested design includes the UCC5880-Q1, a bias-supply power module, real-time control MCUs and high-precision sensing.