Dear All,
1. I already generate the pwm .but that configuration was need to be confirm. configuration attached here.
2. if configuration was not correct .How to generate Complementary pwm .
3. how calculate the duty ratio & switching frequency of Rx66T controller.
Hi Raja, I hope you’re doing well.
If you’re willing to generate a complementary symmetric PWM using MTU3-4 you can follow these steps:
Your initial setup is correct. and can adjust its values based on the below information
You can utilize the configuration for generating a 3-phase phase complementary PWM :
Here’s the output for the above setup:
According to my setup, ‘Timer operation period’ specifies the carrier frequency of all the channels. (Which is 1KHz here).
‘MTU3.TGRB’ specifies the duty cycle of the MTIO3B related output pins
‘MTU4.TGRA’ specifies the duty cycle of the MTIO4A related output pins
‘MTU4.TGRB’ specifies the duty cycle of the MTIO4B related output pins
The value of the duty cycle is determined in this way:
MTU3.TGRB/MTU3.TGRA (4000/15900) for MTIO3B related output pins
MTU3.TGRB/MTU4.TGRB (2000/15900) for MTIO4A related output pins
MTU3.TGRB/MTU4.TGRB (1000/15900) for MTIO4B related output pins.
And about the output channel configuration options, those determine the active-high, and active-low state for each channel and are hardware-specific features that you’ll need to choose based on your H-bridge driver trigger signals.
If you need to adjust those settings in runtime and for motor control, you’ll need to go through different examples which are provided in the below links.
First, choose the needed PWM mode, then investigate the related sample code explanations and files.
There's a complete guide for different modes of PWM in RX66T with example files, which you can find it on this link. Also, there are more examples of Brushless motors and other motor control applications here.
I hope you’ll find that information useful. Check the links and don’t hesitate to ask further questions if needed.
Best regards, Hossein.
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Dear Hossein,
Sorry for the delay of response. Thank you for your hope full support. i have one doubt on count clock selection. is it possible to use main clock 120MHz either 160 MHz ?.
Hello dear Raja.
MTIOC3A toggle output is optional and you can use it for refrence or some synchronization if needed, the top waveform shown in figure in the comment above shows that signal.
And about using high frequency clocks, yes you can choose the main clock without prescaler, but usign higher frequencies will result in higher output frequency. You can adjust it based on you needs.
Hi Hossein,
please clarify , Commanly the Negative channel turn on after the given Deadtime of Positive channel turn off .but here Negative channel turn on then dead time after positive channel turn on it's due to reason of symmetric PWM is it?
Excuse me Raja, I think I mixxed up naming the channels in analyzer app but you can configure the positive, negative channels on your own. Symmetric PWM just makes signals Symmetric with the each other and the MTIO3A signal (the reference timer overflow pulse), you can check out reset synchronized mode to see the difference.
Hello Dear Hossein,
Here i have been tested. the same output was came that's why i asked. Ok i will check.
you're right Raja, the point is, the outputs are set to active-LOW so that the signals are inverse. change the active level settings, based on your hardware.Best regards.
i am using settings are given below . the given timer operation period as 100µs and Deadtime was 10µs .but output of timer operation period was 60µs.then Deadtime is 6.4µs ?.
Configuration:
Timer Operation period :
Deadtime:
Here used PCLK is 120MHz
Could you please check the clock configuration and make sure the related peripheral clock has the intended value? if you're using external crystal, make sure you're using the correct value in setup. Try a different clock setup. it seems the Oscillator's input clock is higher than what is configured in the smart configurator. I'll be happy to hear the results from you. Have a nice time
I will check.