Hi Team,
We're looking for a PWM generator capable of generating square waves at 50KHz and the duty cycle should be controllable from 0 to 100%. We'll use this PWM signals to control the LED brightness. The IC should atleast have 2 PWM outputs and can be controlled individually.
Hi Mukesh,
Right now we have limited options for an I2C controller PWM at that high of a frequency.
Of our existing devices I would suggest the DAC53202.
The PWM generation is done by connecting the voltage output of one channel, the the input of a second channel configured as a comparator:
(This figure shows the DAC539G2, but the same can be done with the DAC53202 for I2C control)
Varying the voltage of the voltage output channel via I2C will update the duty cycle. The frequency is set by an internal function generator that is configured for a sawtooth or triangle wave.
The potential issues you might run into are:
1. You cannot actively change the frequency while the PWM is running. You need to stop the function generator and update the frequency. The duty cycle can be updated while the PWM is running.
2. 50kHz is hitting the limit of what this device can output and as a result the duty cycle resolution won't be very high and the output response is not great at smaller duty cycles. See attached for a test I did at 25kHz. 25KHzPWM .docx
Best,
Katlynne Jones
