TimerBlox LTC6992 PWM variable clock generator at 2.3MHz... out of tolerance or used incorrectly?
The LTC6992 is specified to maintain a specific accuracy up to a frequency of 1MHz. However, it is very much physically capable of running at a higher frequency, which is actually even mentioned on page 22 in the datasheet you linked: &quot;When  operating  with  ISET  outside  of  the  recommended  1.25μA  to  20μA  range,  the  master  oscillator  operates  outside of the 62.5kHz to 1MHz range in which it is most accurate.&quot; It also notes &quot;it is not recommended to operate the master oscillator beyond 2MHz because the accuracy of the DIV pin ADC will suffer.&quot;
It's perfectly fine to run this chip at 2MHz (or even a bit above that). If you want it to not exceed 1MHz, you have to make sure that the SET resistor doesn't drop below 50kOhm.