Three-phase brushless DC motors are being increasingly used in a wide variety of equipment such as electric fans, copiers and electric power tools. Whether the ICs that drive these motors are incorporated in the motor or not, they must be small because many motors are used in each piece of equipment.
Keeping ICs small requires the suppression of heat. To suppress the heat, the power dissipation must be reduced. In general, this means lowering the output MOSFET on-resistance. However, these measures have led to larger chip sizes, and by extension, a larger surface mounting area.
Now, however, Sanken has developed a chip microfabrication technology that reduces the chip size while lowering the output MOSFET on-resistance (to 0.2Ω: half the resistance of previous MOSFETs used by Sanken), reducing the power dissipation, and suppressing heat generation. The result is the SI-6633M, a new 3-phase brushless motor driver IC that realizes an output current of 2 A in a compact surface mounting package (QFN36: 6 mm x 6 mm) that is 60% smaller than previous Sanken ICs.
The SI-6633M also features a range of protection circuits such as an overcurrent protection circuit, overheat protection circuit, undervoltage lockout circuit, and motor lock detector, contributing to higher equipment reliability.
An IC of the same size that does not include an output MOSFET, the SI-6633C, is also available. Attaching a MOSFET with a large capacitance to this IC enables support of an output current of up to 15 A.