Three-phase brushless motor drivers support high speeds for small motors

November 16, 2017 // By Julien Happich
Toshiba Electronics Europe has released two new three-phase brushless motor drivers, the TC78B015FTG for 12V power supply applications and the TC78B015AFTG for 24V applications.

The ICs are delivered in WQFN 36 packages measuring only 5x5x0.8mm, which can be mounted on the limited PCB space found in small high-speed fan motors such as those found in servers.

The ICs also reduce the external component count by incorporating a one-sensor drive and current detection resistor-free system. One-sensor driving reduces the number of hall sensors from three to one and ensures more reliable motor operation than a comparable sensorless drive. The resistor-free current detection system can reduce the power supply rating and eliminate the large resistors previously required. All of these innovations contribute to reduced demand for space on wiring boards.
High speed rotation is achieved with a 150-degree commutation system. Rotation is faster and more stable than with a sine-wave commutation system, and vibration is lower than in a conventional 120-degree commutation system. Adoption of low on-resistance (upper + lower: 0.24Ω (typ.)) reduces heat generation due to the increased motor current found in high frequency drives.

The TC78B015FTG operates with a supply in the range 6V to 22V and the TC78B015AFTG requires a supply in the range 6V to 30V. Both devices support output currents up to 3A and support Hall devices as well as offering a range of protection functions including thermal shutdown, overcurrent detection and motor lock detection.

Toshiba Electronics Europe - www.toshiba.semicon-storage.com


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