TMS320F28027F: IQ Full-Scale Frequency

Jack Tan80

Part Number: TMS320F28027F

Dear Champs,

I have some confusion about the IQ Full-Scale Frequency mentioned in InstaSpin foc&motion user guide.

The text highlighted with red bottom line shows that IQ Full-Scale Frequency equals to the motor's absolute maximum electrical frequency, but below text shows that it is recommended to add 20-30% headroom to this value, higher than the maximum expected frequency of the motor.

Can you please help me understand which one is correct? If both of them are correct, how to understand those 2 maximum frequency?

over 5 years ago

0 Yanming Luo over 5 years ago

TI__Guru** 109820 points

Both are correct. The IQ Full-Scale Frequency is a scale value for you to set the target frequency, set an appropriate value that improves the resolution of speed. Actually, it's not very critical since the IQ format is generally IQ24 that it's enough for most cases on resolution and range.

0 Jack Tan80 over 5 years ago in reply to Yanming Luo

Mastermind 7090 points

OK, thanks.

Regarding to the example listed in the user guide, setting IQ Full-Scale Frequency to 1300.0 is allowable, isn't it?

0 Yanming Luo over 5 years ago in reply to Jack Tan80

TI__Guru** 109820 points

It's fine, but it's better to close to the maximum frequency you want.

0 Jack Tan80 over 5 years ago in reply to Yanming Luo

Mastermind 7090 points

Appreciate your effort on helping this.

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TMS320F28027F: IQ Full-Scale Frequency