ROHM provides more than 220 motor driver ICs, which have extensive track records. The motor types covered by these driver ICs run the gamut, including brushed DC motors, stepping motors, single-phase brushless DC motors, and 3-phase brushless DC motors (including high-voltage models). The ROHM lineups of motor driver ICs features high efficiency and reliability supporting broad ranges of voltages, currents and packages, and pin-compatible products are also available.
There are over 20 models of 3-phase brushless DC motor drivers. In addition to commutation angles of 120° and 150°, the wide-ranging lineup includes sinusoidal (180°) commutation method devices, 3 Hall sensor and single Hall sensor type devices, sensorless type devices, pre-driver type devices, and other driver ICs featuring low noise and low vibrations.
Commutation Angles and Features of 3-Phase Brushless DC Motor Drivers
The commutation angles and features of 3-phase brushless DC motor drivers are described below.
Put simply, the closer the commutation angle is to an electrical angle half-cycle, 180°, the higher is the motor efficiency. In the above diagram, the "Sinusoidal commutation" is 180° commutation.
On the other hand, 120° commutation features good switching efficiency and ease of control.
And, the closer to 180° the commutation angle, the greater the improvement with respect to noise, vibrations, and torque ripple. This is easy to understand given the features of commutation angle current waveforms.
Features of ROHM 3-Phase Brushless DC Motor Driver ICs
●Lineups of sinusoidal commutation-equipped driver ICs by sensor type
The series of 3-phase brushless DC motor drivers includes models that adopt sinusoidal commutation for 3 Hall sensor type and single Hall sensor type designs. Whichever sensor design is used, low noise and low vibrations can be achieved through adoption of sinusoidal commutation.
The diagrams below compare 150° commutation with the BD63251MUV sinusoidal commutation driver IC. On the left, whereas the motor current waveform for sinusoidal commutation is smooth, in 150° commutation, distortion inevitably occurs in the current waveform. On the right, the relative noise levels are compared; under sinusoidal commutation, we see that there is no spike in noise level as is the case in 150° commutation, and noise is reduced.
●Support for 3 Hall sensors, single Hall sensor, sensorless designs
In addition to models for 3 Hall sensor designs, models are available for single Hall sensor and sensorless designs to reduce the number of components used and cut space requirements. The optimum solution for a given application can be provided.
●Broad range of driving voltages supported by combining pre-drivers and power transistors
The BD63001AMUV and BD63002MUV are pre-driver-type motor driver ICs that drive external MOSFETs. The BD63001AMUV can be used under conditions in which the VM voltage is higher than the Vcc voltage, and supports a wide range of driving voltages. And, when used with Vcc=VM, the HLSW pin can be used to set the logic of the UH/VH/WH pin that drives the external high-side transistor, so that the number of external components can be reduced.