Renesas’ Motor Control ICs Simplify Brushless DC Motor Control Design

The RAJ306001 and RAJ306010 are aimed at the three phase Brushless DC (BLDC) motor applications used in a range of battery powered devices. The units combine an MCU (the RL78/G1F) and a pre-driver, with the latter featuring three half bridge gate drivers for N-channel MOSFETS. Renesas asserts that new units will enable designers to “eliminate as many as 30 external components shrinking the solution area by up to 50 percent”

The RAJ306001/10. Image courtesy of Renesas

 

The pre-driver features a 5V regulator, a current sense amplifier, hall IC comparators and a back-EMF amplifier. It also sports necessary safeguards, including protections against over temperature, over voltage, under voltage, and over current as well as motor lock detection. Three half bridge gate drivers feature gate drive peak currents adjustable up to 500mA, selectable gate drive voltage, and a self-aligned dead time generator (SADT) to prevent short-through current.

 

Designed for Battery-Powered Applications

As per Chris Stephens, Vice President of Communications & Motor Control, Industrial and Communications Business Division at Renesas, “Cordless devices offer many conveniences for users, and with the prevalence of motor-based devices such as power tools cutting the cord, demand is high for motor control solutions that deliver higher output levels, long-term operation, and safety improvements while adhering to size and cost constraints.” He goes on to say that “Smaller,lighter, and more reliable with long life than brushed DC motors, BLDC motors are a very effective solution to these challenges, and we are excited to introduce our new sensor-less motor control ICs, which pack the increased control, high-precision, and high-efficiency levels customers require in a smaller package.” 

Renesas offers its own designs for portable power tools and a 24-volt cordless blender based on the RAJ306010. Additionally, the Domel company has affirmed that it will be using Renesas’ motor control ICs in its own upcoming cordless vacuum.

 

Important Features of the RAJ306001 and the RAJ306010

The RAJ306001 and the RAJ306010 support operating voltage ranges of 6 to 30 volts and 6 to 42 volts, respectively.

 

A recommended external circuit example. Image courtesy of Renesas’ datasheet

 

To better manage heat, the devices feature adjustable output current capacity, up to the fully rated 500mA to drive large-capacity MOSFETs,  which makes heat dissipation design easier. This also permits the units to drive the motor MOSFETs at optimum switching timing. Resesas asserts that will reduce MOSFET switching margin times by approximately 90% when compared with conventional systems. This enables both reduced heat generation and more efficient motor drive control. 

 

Applications 

• Water pumps
• Fans
• Pumps
• Robotics and drones
• Power and garden tools
• Vacuum cleaners
• Cleaning robots

 

Physical Considerations

• The motor control ICs are available in 8 by 8 mm 64-pin QFN packages
• Both units are available with temperature ranges of either -40°C to +85°C or -40°C to +105°C

 

Safety and Regulatory

• EC 60730 safety standard support

 

Getting to Market Faster

A Renesas Solution Starter Kit (RSSK) is offered as an aid to developers working with the new ICs. The RSSK includes a development board, motor, and reference firmware, allowing engineers to begin conducting real-time analysis, allowing faster and more efficient evaluation of their motor control designs.

 

About Renesas

Renesas is a global leader in microcontrollers, analog, power, and SoC products, Renesas provides comprehensive solutions for a broad range of automotive, industrial, home electronics, office automation, and information communication technology applications that help shape a limitless future