ROHM offers over 220 kinds of motor driver ICs, which have extensive track records. The types of motors supported are highly diverse, including brushed DC motors, stepping motors, single-phase brushless DC motors, and 3-phase brushless DC motors (including high-voltage models); there are lineups of products featuring high efficiency and reliability over a broad range of voltages, currents, and packages, and pin-compatible products are also available.
There are over 30 models of single-phase brushless DC motor drivers, supporting various driving methods and control technologies necessary for quiet operation and high efficiency. This lineup of drivers includes such features as sinusoidal driving, advance angle control driving, wind loss correction, I/O slope setting, improved back electromotive force jump, and standby functions.
Driving Method and Features of Single-Phase Brushless DC Motor Drivers
Here the driving method and driving waveform of ROHM single-phase brushless DC motor drivers are presented. Switching driving is by standard PWM driving, and output switching is comparatively fast, so that efficiency is high, but due to the sudden transitions of the coil current, there is an adverse effect on quietness. BTL driving is linear voltage driving by bridged driver amplifiers. Through soft switching, quietness is achieved, but efficiency suffers. PWM soft switching driving is a driving method in which, by using "soft" switching in output rising/falling intervals, distortion in the coil current is reduced and quietness is improved while achieving high efficiency. Sinusoidal driving is a driving method in which a coil current adjustment function is added to PWM soft switching driving; because a coil current that is close to a sine wave can be used for driving, extremely quiet driving is possible.
Features of ROHM Single-Phase Brushless DC Motor Drivers
In sinusoidal driving, on the other hand, by providing a function for adjustment of the coil current in PWM soft switching intervals by an external voltage, the coil current waveform can be smoothed and made to approach a sine wave. Distortion in the coil current waveform is further reduced, to achieve enhanced quietness.
This function reduces power consumption of the motor driver while the motor is stopped. By setting the PWM signal duty to 0%, the IC is put into a standby mode.
Products provided with standby functions