Efficient motor control for e-bike applications

Efficient motor control for e-bike applications

Since the 1990s, e-bikes have been steadily growing in popularity across the globe, with the market expecting to grow to around 7 million units by 2025. Although the range concerns surrounding automobiles are not as predominant in the e-bike market, it is still essential that consumers can enjoy the advantages of their electrically supported bicycle without the need to charge it up after every journey.

The growth in e-bikes has been made possible due to the availability of highly efficient motors, high-density batteries, and low-loss drive implementations for motor control. On the motor drive side, highly integrated microcontroller (MCU) solutions are being continuously refined. Today’s MCUs integrate a competent analog front-end and highly configurable timers, coupling them with motor control peripherals that move the complexity of field-oriented-control (FOC) from the software to the hardware domain.

Devices such as the TXZ family of Arm® Cortex® based MCUs integrate a Vector Engine (VE). The latest iteration of this peripheral not only implements the Park-Clarke transformations required for motor control but is also tightly coupled with the other on-chip peripheral needed for accurate motor control. This includes the pulse-width-modulation (PWM) timers and the analog-to-digital converter (ADC). Such tight integration simplifies configuration, ensures accuracy and efficiency in control, and leaves the processing core with much more time to execute other application functions.

In order to ensure a highly efficient drive implementation, such MCUs should be coupled with low on-resistance MOSFETs. Here the focus also broadens to cover the need for compact packaging and excellent thermal dissipation. Devices such as the UMOS IX low voltage (LV) MOSFETs from Toshiba provide the perfect partner to such motor control implementations. This latest generation of devices has reduced gate charge and recovery charge while also reducing on-resistance (RDS(ON)).

Advanced packaging for power devices also needs to be taken into consideration, allowing developers to ensure that any heat generated is dissipated appropriately. Packaging technology, such as the DSOP Advance, are surface mount solutions that provide thermally conductive metal heat spreading pads on both the top and bottom sides.

To find out more about how these technologies can be used to develop energy efficient e-bike applications, take a look at our latest whitepaper:

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