Most robotic motors use outdated IGBTs. They get sizzling and take up area. A brand new GaN design consumes much less vitality, is extra compact, and displays improved efficiency.
Most servo drives in industrial and collaborative robots face effectivity and dimension limitations because of using IGBT-based inverters. These drives, which normally function from a single-phase 200–230 VAC enter and produce a 320 VDC bus with enter energy beneath 3 kW, typically use IGBTs switching at 8–16 kHz. The issue is that IGBTs have excessive energy losses, which require cumbersome warmth sinks that may make up over 30% of the inverter’s dimension. This reduces energy density and provides weight—each important considerations for motor-integrated servo drives in robotic arms and manufacturing facility automation, the place compact, light-weight methods immediately have an effect on movement efficiency.
TIDA010255, a reference design from Texas Devices (TI), addresses these points by implementing a high-efficiency 3-phase energy stage using six fast-switching GaN FETs. These gadgets combine drivers, safety, and temperature reporting, and are managed by a sizzling facet MCU. By utilizing GaN as a substitute of IGBTs, the design achieves considerably greater switching effectivity, even inside the similar PWM frequency vary, reaching a peak effectivity of 99.4% at 16 kHz PWM. The result’s over 4 instances decrease energy loss in comparison with conventional IGBT inverters at 7 ARMS output present. This enchancment helps smaller kind components, greater energy density, and lowered thermal necessities, serving to meet IEC 61800-9 vitality class IES2 requirements.
The inverter design consists of built-in drivers, safety, and temperature monitoring options to simplify circuit design and enhance reliability. Built-in buck converter modules with inductors and bootstrap energy provides cut back exterior element rely and general footprint.
Exact present measurement is achieved utilizing shunt resistors and remoted delta-sigma modulators for phase-current sensing, guaranteeing correct and linear outcomes. As a result of the MCU floor is tied to the ability floor, DC-link and section voltage sensing don’t require isolation. A small, non-isolated delta-sigma modulator measures the DC-link voltage, whereas analog phase-voltage suggestions allows the analysis of sensorless management methods, corresponding to InstaSPIN-FOC.
For analysis, the design contains a 3.3 V I/O interface with a 180-pin MCU connector and a typical header for interfacing with different controllers. It was examined at 320 VDC and 16 kHz PWM and not using a warmth sink, offering a steady 3-phase output of as much as 7.7 ARMS at room temperature. For greater present or temperature testing, a warmth sink will be connected to the PCB via the supplied mounting holes.
This makes the reference design appropriate for engineers creating single and multi-axis servo drives for industrial and collaborative robots. It demonstrates how GaN-based inverters can cut back vitality consumption, lower inverter dimension, and enhance energy density, key enhancements for compact motor-integrated servo drives utilized in 6-axis robotic methods and different manufacturing facility automation functions.
TI has examined this reference design. It comes with a invoice of supplies (BOM), schematics, meeting drawing, printed circuit board (PCB) format, and extra. The corporate’s web site has further information concerning the reference design. To learn extra about this reference design, click on right here.
