Analog Devices technologies and system-level solutions for intelligent motion applications are enabling higher levels of performance while reducing energy consumption and downtime. Figure 5 outlines a typical motor drive signal chain that comprises six key blocks. Each block outlines an ADI solution.
Power electronics provide the power conversion in a motor drive system. For high voltage systems (>100 V), an isolated gate driver is used to drive the power semiconductors. ADuM4122 is a single-gate isolated gate driver with 3 A short circuit (<3 Ω). It supports functional or reinforced isolation up to ~800 V DC bus with slew rate control for EMI/power loss optimization. It also supports high common-mode transient immunity (CMTI) and low propagation delay for use with SiC and GaN power semiconductors. ADuM160N multichannel digital isolators can be used to isolate PWM signals for use with integrated power modules (IPM) that integrate the gate driver with the power semiconductor. The ADuM6028 isolated power device can be used in conjunction with digital isolators, isolated transceivers, and isolated data converters to provide a very small 8-lead solution that is fully safety certified and ready to use.
For low voltage systems (<100 V), the LTC7060, a 100 V half-bridge driver with floating grounds and programmable dead time or the LTC7000, a 150 V protected high-side NMOS static switch driver with PassThru™ technology and adaptive shoot-through protection can be used to drive low voltage semiconductors. LTC7000 also supports programmable dead time for efficiency optimization, enhanced current control, and slew rate control for EMI reduction.
For isolated current sense measurement, the ADuM7701 is a high performance, second-order, sigma-delta (Σ-Δ) modulator that converts an analog input signal into a high speed, single-bit data stream with on-chip digital isolation based on Analog Devices iCoupler® technology. ADuM7703’s low offset drift (0.6 μV/°C max) reduces torque ripple and is packaged in a compact 8-lead package with integrated LDO to simplify power supply design and reduce board area. Its 150 V/ns min CMTI rating enables use with GaN and SiC power electronics.
AD8410 high voltage, current sense amplifiers provide a high gain (20 V/V, 50 V/V, 100 V/V) and low offset drift (~1 μV/°C) with high bandwidth (2 MHz) for optimum current control. AD8410 also includes bidirectional current measurement input up to 100 V common-mode input. The LTC6102 precision zero-drift current sense amplifier ensures accuracy across a wide range of operating conditions and can be powered from high-side voltages up to 100 V in shunt-based current sensing applications.
Position feedback is used for direct position control or for inferring rotational speed and implementing machine speed control. ADA4570 and ADA4571 integrated AMR angle sensors with integrated signal conditioners enable higher absolute accuracy position sensing for motor drive and servo applications (<0.1° error, <0.5° over life/temperature). They are robust in magnetically harsh environments, support wide air gap tolerances without degradation of angular error (unlike Hall/GMR/TMR), and simplify system design considerations. The ADA4570 and ADA4571 are not affected by dust or dirt when compared with optical sensors in industrial applications, and they have very low latency compared to digital output solutions on the market with built-in calibration engines. ADA4571 produces two single-ended analog outputs (sine and cosine) that indicate the angular position of the surrounding magnetic field, while the ADA4570 produces two differential analog output pairs. A dual version of the ADA4571 (ADA4571-2) is also available where full redundancy is needed in safety critical applications.
The AD7380 is a 4 MSPS dual simultaneous sampling, 16-bit SAR ADC that provides precision, throughput, and minimal size for encoder applications. AD7380 is in a small package size (3 mm × 3 mm) for miniaturization of the encoder with 4 MSPS throughput for minimal latency and fast control loop transient response. The AD7380 oversampling engine allows higher accuracy for slower operating conditions.
Vibration and shock sensors are being integrated into the encoder or the motor to provide asset health insights. The ADXL1002 ultralow noise (25 μg/√Hz in ±50 g range), high frequency, ±50 g MEMS accelerometer provides high data bandwidth vibration sensing up to 11 kHz (3 dB point) with a resonant frequency of 21 kHz. ADXL1002 provides a lower cost and lower power alternative to piezoelectric sensors. ADXL1002 enables monitoring of slow rotating equipment down to DC while also reducing calibration requirements when compared to piezo sensors. ADXL354 is a low noise, low power, 3-axis MEMS accelerometer in a small (3 mm × 5 mm) package with a digital interface, SPI (3- and 4-wire), and I2C to provide a compact solution for vibration sensing integration in encoders.
The ADI OtoSense™ Smart Motor Sensor is an AI-based, full turnkey hardware and software solution for condition monitoring of electric motors, combining best-in-class sensing technologies with leading-edge data analysis. Agnostic of motor type, ADI OtoSense SMS covers the most critical diagnostics, translating data into actionable insight that enables you to forecast maintenance cycles and avoid unplanned downtime.
Smart manufacturing is based on a network of intelligent motion applications sharing data between the assets and the higher-level control and management network. ADI’s robust, low power, and low latency PHYs include the ADIN1200 (10/100) PHY and the ADIN1300 (10/100/1000) PHY. Both these Industrial Ethernet PHYs were developed for industrial applications that require operating ambient temperature up to 105°C and have been extensively tested to EMC and robustness standards to operate in harsh industrial applications. Low latency PHYs enable a lower cycle time network that can support more devices connected to the network and meet the timing requirements for complex, high performance deterministic motion applications. For deterministic Industrial Ethernet connectivity, ADI’s layer 2 Industrial Ethernet embedded 2-port switches. fido5100 and fido5200 support PROFINET, Ethernet/IP, EtherCAT, Modbus TCP, and Ethernet POWERLINK Industrial Ethernet protocols with any processor, any protocol, any stack.
The motion controller provides the processing engine to generates the PWM signals to drive the power semiconductors and receives the current and position feedback signals to control the motors speed and torque. Robust, high ambient, high power density power management solutions are required to power the controller, which is often an FPGA or a processor with optional power supply sequencing and power telemetry capabilities. Analog Devices’ Power by Linear™ power management ICs and power modules provide the foundation for powering today’s and tomorrow’s intelligent motion applications. The motion controller is often located in a central rack that needs to communicate over a large distance to the encoder. This is where ADI’s isolated and nonisolated RS-485 transceivers are used for serial communication of the encoder position feedback information to the motion controller. The ADM3066E, a ±12 kV IEC ESD protected, full-duplex 50 Mbps RS-485 transceiver, provides a high bandwidth, high ambient (125°C), robust communications solution in a small 3 mm × 3 mm package size for encoder applications.