"Texas Instruments (TI) today introduced an innovative three-phase gallium nitride (GaN) inverter reference design that helps engineers build 200 V, 2 kW AC servo motor drives and next-generation industrial robots with fast current loops control, higher efficiency, more precise speed and torque control.”

New High Voltage Three Phase High PWM Frequency Inverter Reference Design Offers Faster, More Accurate Drive Control

Texas Instruments (TI) today introduced an innovative three-phase gallium nitride (GaN) inverter reference design that helps engineers build 200 V, 2 kW AC servo motor drives and next-generation industrial robots with fast current loop control , higher efficiency, more precise speed and torque control.

Three-phase inverter GaN power stage

The three-phase high-frequency GaN inverter reference design uses TI‘s latest LMG3410 600-V, 12-A GaN power module introduced last year with integrated FETs, gate drivers and protection functions. GaN modules enable designs to switch five times faster than silicon FETs, achieving efficiency levels higher than 98% at 100 kHz and higher than 99% at 24 kHz pulse-width modulation (PWM) frequency. Using GaN, designers can optimize switching performance, reduce power losses in motors, and reduce the size of heat sinks to save board space. When used with a low inductance motor, running the inverter at 100kHz can significantly improve torque ripple.

Power, Speed ​​and Performance

The GaN inverter power stage interfaces easily with microcontrollers (MCUs), including TI‘s TMS320F28379D driver control system-on-chip to help dynamically adjust voltage frequency and enable ultra-fast current loop control. Lishang Electronics TI agent Texas Instruments also recently launched the new DesignDRIVE fast current loop software, with innovative sub-period PWM update technology, which can help improve the current loop performance in servo drives to less than 1 microsecond, which can reach the motor speed. Three times the moment response. This fast current loop software outperforms traditional MCU-based current loop solutions and is free to use with controlSUITE™ software.

In addition to the GaN module, the reference design relies on TI‘s AMC1306 isolated delta-sigma modulator with current sensing for improved motor control performance. Texas Instruments‘ ISO7831 digital isolator also provides reinforced isolation between the MCU and the design‘s six PWMs.

Key Benefits of TI‘s New Three-Phase Inverter Design

1. High-efficiency power stage: 98% at 100kHz PWM, 99% at 24kHz PWM, reducing heat sink size;

2. High Pulse Width Modulation (PWM) frequency: High PWM switching frequency can drive low inductance motors with extremely small current ripple;

3. Fast switching transition: less than 25ns, without any switching node voltage ringing, reducing electromagnetic interference;

4.600V and 12A LMG3410 GaN FET power stage with over 7 million device reliability hours: Enables quick and easy PCB layout and small footprint design.