In this interview George Lakkas, Automotive Marketing Manager for High-Power Drivers at Texas Instruments spoke to Electronics Maker about TI products For EV applications and its advancements.
1. Please share your insights on SiC and GaN devices market growth for EV applications.
As EVs continue to grow in popularity, semiconductor innovations in traction inverter systems are helping overcome critical barriers to widespread adoption. Automakers can build safer, more efficient and more reliable silicon carbide (SiC)- and insulated-gate bipolar transistor (IGBT)-based traction inverters by designing with the UCC5880-Q1, featuring real-time variable gate-drive strength, Serial Peripheral Interface (SPI), advanced SiC monitoring and protection, and diagnostics for functional safety.
The UCC5880-Q1 enables higher system efficiency and reliability with reduced system size and lower BOM cost with real-time variable gate drive strength and advanced SiC monitoring and protection for high-voltage automotive and industrial applications. The UCC5880-Q1 expands TI’s portfolio of functional-safety-compliant drivers and overall traction-inverter-specific drivers with real-time variable gate drive feature, which offers substantial advantages in high-power and high-voltage traction inverter systems.
2. What are the advancements in EV Tractor inverter design?
Traction inverters are the main consumer of battery power in electric vehicles (EVs), with power levels reaching 150 kW or higher. The efficiency and performance of traction inverters directly impact an EV’s driving range on a single charge. Therefore, to build the next generation of these systems, the industry has widely adopted silicon carbide (SiC) field-effect transistors (FETs) to enable higher reliability, efficiency and power density. Traction inverters nowadays are combined in the same box as the OBC and DC/DC converter in what is known “One-Box” designs.
The space allowed for traction inverters is getting tighter so power density is a key care-about especially for designs that have traction inverters on each axle or even on each wheel.
SPI-based ISO26262-compliant gate drivers help enable higher power density, efficiency, and functional safety up to ASIL-D, with integration of key functions such as Active Short Circuit Protection, ADC channels, Built-In Self Test, VCE Clamp, and Gate Threshold Monitoring at every key-on in additional to several other monitoring, and protection functions all with multiple programmable thresholds.
Engineers can further reduce components and quickly prototype a more efficient traction inverter system using the SiC EV Traction Inverter Reference Design. This customizable, tested design includes the UCC5880-Q1, a bias-supply power module, real-time control MCUs and high-precision sensing.
3. What are the key challenges in designing EV tractor inverters?
Designers of high-voltage applications like traction inverters face a unique set of challenges to optimize system efficiency and reliability in a small space.
The need for higher reliability and power performance for EVs is continuously growing, as efficiency gains have a direct impact on operating range improvement per charge. But achieving any increase in efficiency is difficult for designers, given that the majority of traction inverters already operate at 90% efficiency or higher.
The new UCC5880-Q1 helps control SiC gate drive strength via slew-rate voltage control in ~25 microseconds across operating conditions. For batteries charged at 80% to 100%, using a lower drive strength reduces EMI and risk of voltage overshoot, whereas for batteries charged less than 80%, which is roughly ¾ of the battery charge cycle, using a higher drive strength increases system efficiency by reducing switching losses.
4. How do SiC gate drivers help in maximizing EV range?
With theUCC5880-Q1 gate driver designs can vary the SiC slew rate in real time in steps between 20 A and 5 A, and increase system efficiency by > 2% by minimizing SiC switching power losses, resulting in up to 7 more miles of EV driving range per battery charge.
5. What are the key features of your recently introduced gate driver IC UCC5880-Q1?
TI debuted a highly integrated, functional safety-compliant, isolated gate driver that enables engineers to design more efficient traction inverters and maximize electric vehicle (EV) driving range. The new UCC5880-Q1 is reinforced dual-output, split-output isolated gate driver with real-time variable gate drive strength via both a 4MHz bidirectional SPI bus and three (3) digital input pins enabling designers to set the drive strength at power-on without have to use the SPI registers.
The UCC5880-Q1 integrates a host of protection and monitoring features including a gate threshold voltage measurement feature that can be used to monitor the power switch health at every EV key-on. These features enable EV powertrain engineers to increase efficiency, and power density and reduce system design complexity and cost while achieving their safety and performance goals.
6. How will this product help in reducing cost and complexity?
The UCC5880-Q1’s SPI programmability and integrated monitoring and protection features can reduce design complexity as well as external component costs. Integrated diagnostics and protection features, such as primary and secondary active short circuit protection, two (2) 10-bit ADC channels, DESAT and gate voltage monitor, and gate voltage threshold monitoring, in a single chip, eliminate the need for external components. Other benefits include:
- Integrated Serial Peripheral Interface (SPI) and digital input pins for programmability and design flexibility
- With integrated diagnostics and protection features, the UCC14141-Q1 & UCC5880-Q1 chipset reduce PCB space by up to 30% compared to discrete implementations, enabling powertrain integrated architecture designs that combine the traction inverter with other sub-systems, such as on-board chargers and DC/DC converters.
- Saves 30+ discrete components and reduces gate driver board height to < 3.6mm
7. What are the other innovations you are showcasing at PCIM Europe?
At PCIM Europe, TI showcased high-voltage innovations for a sustainable future. Demonstrations showcased system-level innovations for gallium nitride (GaN)- and SiC-based designs as well as other TI technologies to increase power density and efficiency for EVs, power supplies, energy storage systems and more. Visit TI.com/PCIM for more information.
