Renesas Announces New Production-Ready RISC-V-based Motor Control Processor

With the recent announcement of the R9A02G020 motor control Application Specific Standard Product (ASSP), Renesas Electronics Corporation offers motor control system designers a complete and turn-key solution for low-power motor control design in applications such as home/building automation, healthcare devices, and home appliances like air conditioners and refrigerators.

 

Reducing Design Time for Motor Control Applications With RISC-V

The ASSP is shipped pre-programmed with motor control software, reducing time to market and eliminating costs associated with RISC-V-related tools and software. The application code was developed with BFG Engineering and DigiPower (HK) Technology Ltd., independent design houses with proven expertise in motor control applications and well-resourced programs to support customer design initiatives.

 

Motor control ASSP for consumer motor applications. Image used courtesy of Renesas Electronics

 

Three-phase Motor Control Simplified

The R9A02G020 is purpose-built for coordinating low-power, 3-phase motor control applications in consumer appliances, power tools, and even drones. The chip features a 32 MHz RISC-V Andes N22 Core with 48-KB Flash and 16 KB of SRAM memory. The onboard analog package includes a 12-bit ADC, x3 Programmable Gain Amplifiers (PGAs), x2 High-Speed Comparators, x2 8-Bit D/A Converters, and Temperature Sensor. Communications are through a Serial Communication Interface (SCI), and the unit can operate off a supply voltage between 2.7 V and 5.5 V.

The solution can support a wide range of motor sizes, up to 100 V depending on the rating of the supported half-bridge drivers and MOSFETs. There are three PWM outputs to each of the motor's three phases (U, V, and W). In the reference application, 48 V is supplied to the motor half bridge networks with 14 V generated from an external synchronous buck converter (RAA211820) to power the Gate Drivers (~3 A) and the 5 V LDO (~ 100 mA) that provides power to the ASSP.

Current sense data from each phase shunt resistor is monitored through the comparator analog inputs to feed to the control algorithm.  A separate GPIO input is used to receive an overcurrent alarm from an external comparator (ISL28915FH62). A wide range of additional input channels (UART, Analog, GPIO, I2C) are provided to incorporate inputs from Hall sensors, motor position encoders, or an inductive position sensor. The PMOD interface, with I2C or serial port, supports the connection of external environmental sensors or wireless connectivity if desired.

 

R9A02G0020 three-phase motor control application. Image used courtesy of Renesas Electronics

 

The R9A02G020 ASSP EASY Motor Control Kit is offered as a test platform and reference design to help designers with evaluation and testing for AC Brushless Motor applications. A user-friendly PC Graphical User Interface (GUI) allows easy access to motor performance parameters and offers real-time motor control tuning for application optimization without extensive software development.

 

R9A02G0020 benchtop evaluation set up. Image used courtesy of Renesas Electronics

 

RISC-V Embedded Processing

Renesas has taken a proactive approach to developing products based on the emerging RISC-V IP. In addition to its new motor control ASSP, the company recently introduced a 64-bit general-purpose RISC-V CPU and announced development plans for an automotive solution.

RISC-V was originally started by a professor and two graduate students from the Parallel Computing Laboratory at the University of Berkeley in 2010. The RISC-V consortium currently has over 3,100 members across 70 countries who contribute to and collaborate on the open-source instruction set architecture (ISA).

Andes Technology Corp, an embedded processor intellectual property supplier based out of Hsinchu City, Taiwan, developed the RISC-V processing IP used in the R9A02G020.

 

Featured image used courtesy of Adobe Stock