MSP430F5249: What is the range of acceptable ESR for the crystal?

Hello Lauren,

We do not specify ESR values for requirements of XT2. However, we do specify Oscillation Allowance which is effectively the max ESR allowed with a safety factor test result of 5. For more information about the relationship of ESR and OA, see section 2.2 ESR values of the following app note: MSP430 32-kHz Crystal Oscillators

Note: the app note linked is centered around LFXTALs; however, the same principles apply for HFXTALs.