Aug 04, 2019
01:21 AM
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Aug 04, 2019
01:21 AM
Hi,
I am looking at using the IFX007 [1] in a BLDC driver setup, the PWM frequency
that the controller generates is about 100kHz. have been looking at what max PWM frequency
the IFX007 supports.
The documents at some place states eg: 20kHz, somewhere else states 25kHz and elsewhere
30kHz. I am unable to find a location where it states the absolute maximum for the device.
Can someone clarify, please ?
[1] https://www.infineon.com/cms/en/product/power/motor-control-ics/intelligent-motor-control-ics/single...
Thanks,
Manu
I am looking at using the IFX007 [1] in a BLDC driver setup, the PWM frequency
that the controller generates is about 100kHz. have been looking at what max PWM frequency
the IFX007 supports.
The documents at some place states eg: 20kHz, somewhere else states 25kHz and elsewhere
30kHz. I am unable to find a location where it states the absolute maximum for the device.
Can someone clarify, please ?
[1] https://www.infineon.com/cms/en/product/power/motor-control-ics/intelligent-motor-control-ics/single...
Thanks,
Manu
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Aug 04, 2019
10:02 PM
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Aug 04, 2019
10:02 PM
Hi Srivatsa,
Thanks for the details. Much appreciated. Will try the device.
Best Regards,
Manu
Thanks for the details. Much appreciated. Will try the device.
Best Regards,
Manu
2 Replies
Aug 04, 2019
08:42 PM
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Aug 04, 2019
08:42 PM
Hi,
As per page 22 of device datasheet, for the selection of the max. PWM frequency the chosen rise/fall-time and the requirements on the duty cycle have to be taken into account. We recommend a PWM-period at least 10 times the rise-time.
Example:
Rise-time = fall-time = 0.22 µs as per the min. specifications in table 7 of device datasheet.
=> T-PWM = 10 * 0.22 µs = 2.2 µs.
=> f-PWM_max = 450 kHz.
This is a theoretical value. It must be verified in real application. Power dissipation limits of the device should also be considered.
For your switching frequency of 100 kHz, if we back-calculate as per above, rise-time+fall-time = 1 us, which is well within the device specifications.
As per page 22 of device datasheet, for the selection of the max. PWM frequency the chosen rise/fall-time and the requirements on the duty cycle have to be taken into account. We recommend a PWM-period at least 10 times the rise-time.
Example:
Rise-time = fall-time = 0.22 µs as per the min. specifications in table 7 of device datasheet.
=> T-PWM = 10 * 0.22 µs = 2.2 µs.
=> f-PWM_max = 450 kHz.
This is a theoretical value. It must be verified in real application. Power dissipation limits of the device should also be considered.
For your switching frequency of 100 kHz, if we back-calculate as per above, rise-time+fall-time = 1 us, which is well within the device specifications.
Aug 04, 2019
10:02 PM
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Aug 04, 2019
10:02 PM
Hi Srivatsa,
Thanks for the details. Much appreciated. Will try the device.
Best Regards,
Manu
Thanks for the details. Much appreciated. Will try the device.
Best Regards,
Manu