ON Semiconductor — Autonomous Robots: Solutions for Motor Control, Image Sensing and Wireless Communication

ON Semiconductor offers a comprehensive range of power management, connectivity and sensor products which match the needs of advanced robot systems. In industry, robots are used to achieve higher productivity, lower cost and greater safety in the performance of repetitive tasks. As manufacturing becomes more integrated, robots will play an increasing role in a variety of assembly tasks, offering greater functionality, flexibility, range of motion, speed and precision.

The successful development of the next generation of autonomous industrial robots calls for new component technology in the fields of motor control, image sensing and short-range wireless communication. This Design Note introduces developments from ON Semiconductor which designers of autonomous robot systems can apply in new projects, as shown in Figure 1.

Fig. 1: New autonomous robot designs can benefit from an array of ON Semiconductor component technologies

Efficient motor control for autonomous driving robots

ON Semiconductor offers a wide range of trench MOSFETs: when used in the inverter power stage of a motor, these MOSFETs can help the system designer to implement an efficient motor-control system, as shown in Figure 2. To prolong the lifetime of a motor, it is important to control the operating temperature carefully. An increase of 10°C in operating temperature can reduce the lifetime of a motor by half. To extend this lifetime, designers can use ON Semiconductor’s PowerTrench® MOSFETs: this line of devices, which includes the FDMS861xx family, helps to reduce EMI and voltage spikes and to increase power output, while maintaining good heat dissipation.

The three-phase inverter in a Brushless DC (BLDC) motor can benefit from the use of MOSFETs which produce very low conduction losses. The NTMFS5xxxxx family of MOSFETs from ON Semiconductor feature the industry’s lowest on-resistance and have soft body-diode characteristics which enable increased application efficiency and reduced switching noise in motor drives and battery management systems.

Current-sense amplifiers, such as the NCS2xx family, are used to monitor current in the inverter in order to provide important safety and diagnostic information to the motor-control system, and to perform over-current protection and support accurate power delivery.

ON Semiconductor’s Intelligent Power Modules (IPMs) for motor control contain all the components needed for a BLDC drive stage integrated in a single package: this includes the six MOSFETs or IGBTs as well as a driver IC with integrated logic, control, detection and protection circuits. Because they are highly integrated, IPMs reduce system size and are easy to implement in motor-drive designs, helping to cut development time. They also benefit from thermally enhanced packaging, which helps to improve system reliability.

Control and safety components

One of the primary objectives for designers of autonomous industrial robots is to enable more accurate motion while accelerating production workflows and keeping the factory safe for human operators.

To support these requirements, ON Semiconductor offers a market-leading portfolio of CMOS image sensors which are notable for their very high resolution and integrated features.

Although the architecture of a CMOS image sensor requires that each row of pixels is digitized individually, some devices can produce a global shutter read-out: the MT9V034 and AR0144 from ON Semiconductor both offer this feature. A global shutter eliminates the unwanted motion artifacts produced by image sensors that have a rolling shutter, and supports 3D stereo synchronization for depth mapping.

Bluetooth wireless communication for low power consumption

ON Semiconductor’s RSL10 is a multi-protocol radio System on Chip (SoC) which brings ultra-low power Bluetooth® Low Energy radio technology to autonomous robot designs. Offering the industry’s lowest power consumption, the RSL10 provides advanced wireless features while optimizing system size and extending battery run-times. The highly integrated radio SoC features a dual-core architecture and a 2.4GHz transceiver, providing the flexibility to support Bluetooth Low Energy and proprietary or custom 2.4GHz radio protocols.

Silicon Technology Lower RDS(ON) T6, T8, PTNG Reduce QRR/TRR T8, PTNG Lower CISS T8, PTNG Improved QGD/QGS T8, PTNG Lower RG T6, T8, PTNG
Packaging Technology Improve die to package ratio PQFN: 8x8, 5x6, 3x3 Reduce parasitic inductance Power clips: 8x8, 5x6, 3x3 Improve thermal performance Dual cool packaging Increase current capability 8x8, D2Pak7L, TOLL
Application Benefits Lower conduction loss Lower switching loss Simpler gate drive Reduced EMI Reduced voltage spike No gate bounce Higher power density Reduced system cost

Fig. 2: ON Semiconductor MOSFET technology is ideally suited to motor-control applications

Proximity Sensors

MOSFETs for Battery Management and Protection

Current-sense Amplifiers for High- or Low-side Sensing