I have been experimenting with PWM on a PIC 16F877A. Initially, I used an example program that came with my development board & tweeking the values to see what effect they had on the trace of my oscilloscope. Having done that, I am now attempting to get a waveform to my specifications. I am having a little difficulty in understanding the Microchip datasheets (or maybe it is just general ignorance!). I just cannot fathom out what is meant by PWM Resolution. I am a novice to electronics, but I understand that, say, a 10-bit A/D converter would give you a reading of 0-1023 or an 8-bit one a reading between 0-255, but the datasheet gives a formula to work out the *Maximum PWM Resolution* in bits. I don't fully understand why that is a variable. ATM, I am guessing that the higher the frequency of the PWM the less resolution you have available to specify the duty cycle. So with a low frequency PWM, you could have 10-bits of resolution i.e. the duty cycle could be 1/1024 of the period. A much higher frequency, may only allow you to have 3-bit resolution i.e. 1/8 of the period. Am I on the right track? Thx in advance, Cap'n Ahab
What is PWM Resolution?
Started by ●August 23, 2006
Reply by ●August 24, 20062006-08-24
Cap'n Ahab wrote:> ATM, I am guessing that the higher the frequency of the PWM the less > resolution you have available to specify the duty cycle. So with a low > frequency PWM, you could have 10-bits of resolution i.e. the duty cycle > could be 1/1024 of the period. A much higher frequency, may only allow > you to have 3-bit resolution i.e. 1/8 of the period. > > Am I on the right track?Yes.