Timer and PWM calculations

[lpcware]

Content originally posted in LPCWare by Pranoti on Mon Aug 11 20:32:49 MST 2014
Hello Team,
I am working with LPC4357FET256, please tell me how to calculate PWM frquency and how to set the timer registers for it.

Regrds,
Pranoti

[lpcware]

Content originally posted in LPCWare by Pranoti on Mon Aug 18 04:30:27 MST 2014
HEllo Team,
To drive the motor at 60KRPM we need 90KHz PWM frequency.
I want to know what will be the CPU load when FOC frequency is 90KHz and PWM frequency is 90KHz, also when FOC frequency is 45KHz and PWM frequency is 90KHz.

Regards,
Pranoti

[lpcware]

Content originally posted in LPCWare by Pranoti on Tue Aug 12 23:10:42 MST 2014
HEllo Bavarian,
LPC43xx has motor control PWM which can be used for 3 phase AC and DC motor control aaplication.
Application I am working on is BLDC motor control, so we can use dedicated motor control PWM from LPC43xx.
I want to know what calculation we need to do to achieve 80Khz PWM frequency and how to set which registers related to this.

Regrds,
Pranoti

[lpcware]

Content originally posted in LPCWare by bavarian on Tue Aug 12 08:27:46 MST 2014
The SCT inside the LPC4357 can do the job.

Look on the following webpage and download the SCT Cookbook:

http://www.lpcware.com/content/project/SCTimer-PWM

Using the standard timers would also be possible, but the SCT is a much smarter solution for PWM.
As third option there is the Motor Control PWM.

More software examples might be here

http://www.lpcware.com/content/nxpfile/lpc4350apdlzip

and here

http://www.lpcware.com/content/nxpfile/lpcopen-software-development-platform-lpc43xx-packages


Regards,
NXP Support Team