The PWM page on PJRC website says:
Normally analogWrite(pin, value) is used with the value between 0 to 255, which corresponds to 8 bit resolution. Writing 256 forces the pin always high. Teensy LC &x:w, 3.x support an analogWriteResolution(bits) function, to reconfigure analogWrite.
[...]
To configure both frequency and resolution for matching performance, use the values from this table:
What does "performance" refer to in this case?
The reason I'm asking is that I've had recent problems providing a nice clock signal to external IC. I have experimented with providing 1-20MHz of PWM to provide an ADC with its master clock. It works functionally speaking, but I'm getting problems with clock niceness* which is affecting the SNR performance of the ADC.
*I'm talking about squareness more than anything, I don't have any evidence to suggest drift or other issues exist
** It may be that my problems are related to inductance on the PCB traces / proximity to other traces etc. But I saw this interesting use of the word "performance" and wanted to check here.
*** Is there any other way to improve clock niceness - or at least anything else I can experiment with, e.g. a fixed clock pin on the Teensy4.1?
**** I can't easily test with an external clock, as it's almost impossible finding supplies of a 3.3V oscillator chip right now. I mean - I can cannibalise an Arduino for its crystal but then need to put together a convincing circuit that will give me a nice pure square wave which at that frequency is going to be a problem in itself..
Normally analogWrite(pin, value) is used with the value between 0 to 255, which corresponds to 8 bit resolution. Writing 256 forces the pin always high. Teensy LC &x:w, 3.x support an analogWriteResolution(bits) function, to reconfigure analogWrite.
[...]
To configure both frequency and resolution for matching performance, use the values from this table:
What does "performance" refer to in this case?
The reason I'm asking is that I've had recent problems providing a nice clock signal to external IC. I have experimented with providing 1-20MHz of PWM to provide an ADC with its master clock. It works functionally speaking, but I'm getting problems with clock niceness* which is affecting the SNR performance of the ADC.
*I'm talking about squareness more than anything, I don't have any evidence to suggest drift or other issues exist
** It may be that my problems are related to inductance on the PCB traces / proximity to other traces etc. But I saw this interesting use of the word "performance" and wanted to check here.
*** Is there any other way to improve clock niceness - or at least anything else I can experiment with, e.g. a fixed clock pin on the Teensy4.1?
**** I can't easily test with an external clock, as it's almost impossible finding supplies of a 3.3V oscillator chip right now. I mean - I can cannibalise an Arduino for its crystal but then need to put together a convincing circuit that will give me a nice pure square wave which at that frequency is going to be a problem in itself..