The ECXV-P37C2N-644.5312 from ECS Inc. International is a VCXO with Frequency 644.5312 MHz, Frequency Stability ±25 ppm, Supply Voltage 3.3 V, Current 68 mA, Pulling ±90 ppm. Tags: Surface Mount. More details for ECXV-P37C2N-644.5312 can be seen below.