At the output of the PWM14, a filter (low pass or bandpass) transforms the digital pulse train into an analog voltage. Using a low-pass filter, even a simple RC design, the analog output of the filter is basically Vout = Vcc x Duty Cycle. (This equation assumes that the I/O pin can drive to the Vcc level.) For example, in the top illustration, Vcc is 5.00V, and the duty cycle is 50 percent (since t1 = t2). Therefore, Vout = 5.00V x 50% = 2.5V. In the bottom illustration, both output A and output B have a duty cycle of 25 percent, although output B is a much higher frequency. No matter, the analog level at the output of the filter would be exactly the same: Vout = 5V x 25% = 1.25V. The output is not affected by frequency if the filter is designed correctly.