Drive level is the power required from the oscillator circuit to operate/drive a crystal. The drive level can be calculated as follows:
Drive Level= I
2 * R
L, where I is the current going into the crystal unit and R
L is the effective resistance of the crystal. Also, R
L can be estimated as follows:
R
L= RR(crystal impedance)*(1+C
0/C
L)^2,
C
0: shunt capacitance of the crystal unit
C
L: Load capacitance
In order to estimate the drive level correctly, the current flowing into the crystal needs to be measured accurately. TAITIEN uses current probes to measure the actual current flowing into crystal units to determine the true drive levels for crystals produced by TAITIEN. See picture for the measurement set-up.
