Programmable ICs enable full torque at zero speed for sensorless BLDC motors

Renesas Electronics Corporation has introduced a family of motor driver ICs for BLDC motor applications. The devices implement the company's new, patent-pending technologies that allow full torque from motors without sensors at zero speed, an industry first. The new motor driver ICs allow its customers to develop sensorless BLDC motor systems with higher horsepower and speed at a given torque. They also enhance power consumption and reliability, lowering cost and board space by reducing the number of components designers need.

The company is introducing three new motor driver ICs with the new technology. The RAA306012 65V, three-phase Smart Driver is a standalone device that can be paired with various MCUs from the company or other sources. The RAJ306101 integrates an RX13T 32-bit MCU with the RAA306012 in a single package, decreasing board space and improving cost and reliability. The RAJ306102 integrates a 16-bit RL78/G1F MCU with the RAA306012, delivering similar integration benefits.

The ability to allow full torque at zero speed without sensors is made possible by two of its innovations. EIS provides stable position detection when the motor is completely stopped. Motor Rotor position Identification (MRI) is employed when the motor operates at extremely low speed. At higher speeds, the new motor driver ICs use conventional methods. The new EIS and MRI algorithms include patent-pending technology developed by the company.

"The advantages of sensorless design are numerous, including cost, space, power and reliability," said Davin Lee, vice president of the Advanced Analog Division at Renesas. "Our customers can now enjoy these benefits for systems that require full torque at zero speed. This industry first is a great example of Renesas combining our technical prowess with deep application knowledge to deliver a solution that meets a clear market need."

"We are eager to implement sensorless technology into new products where we previously had to include sensors," said Peter Korošec, president and CEO at Domel Inc., a global supplier of electric motors, vacuum motors, blowers, and components. "This breakthrough from Renesas will enable us to provide new products for our customers with the best available size, cost and reliability."