MCF8316A: Maximum RPM and electrical speed limit

According to the datasheet of MCF8316A, the maximum electrical frequency is “up to 1.5kHz”, which might means it could drive a motor which has 12 poles(6 pairs) with up to 15k rpm. However, another tip points out that maximum motor electrical speed(MAX_SPEED) is a 14bit value and can be set as 0x2710 to achieve 1666Hz motor speed, and “Output PWM Switching Frequency“ has range of 10-75 kHz.

So which parameter would be the hard limit? What would happen if I set MAX_SPEED as 0x3FFF which will bring the electrical frequency up above 1.5kHz? Will the motor operate erratically, or will it experience serious errors and fail to operate?

Cherry Zhou：

Hi,

We're looking into this issue and will get back to you soon.

Thanks

,

Cherry Zhou：

Hi,

Apologize for the delay.

The 1.5 kHz maximum motor electrical speed was determined by the design team though simulations to be the maximum motor speed which we can guarantee that the device will still operate as specified in the datasheet. Exceeding this motor electrical speed can lead to the device not operating as specified in the datasheet which could lead to the device, for example, becoming damaged or voltages not staying within electrical specifications.

Thanks