As per the data sheet doubler can be used in phase sync mode. The LMX2595 is configured for the following setting:
Fvco = 9000 MHz,
VCO2X_EN = '1',
Fout = 18000 MHz,
Fpd = 50 MHz,
N = 180,
Two LMX2595 devices are mounted on separate PCBs, The input reference signal is synchronized for the both the device. the devices are used in the phase synchronized mode. Part to part delay variation is nullified using the MASH_SEED. Now the temperature difference between the is about 2°C. As per the datasheet the delay variation with respect to temperature is +2.5 ps/°C. So the delay variation between the device will be 5ps. Due to the above delay variation, How mush will be the phase difference between the two outputs?