Compact crystal unit preserves ESR characteristics
ESR (equivalent series resistance) characteristics that are usually lost when a crystal is miniaturised, are preserved, says Murata, describing the XRCED series. It is, says the company, the world’s smallest high precision crystal unit for use in mobile equipment and modules that use wireless technology such as WiFi and Bluetooth.
The XRCED series crystal unit uses a technology that is claimed to provide excellent low ESR, and by decreasing the size of the previous crystal unit to 1.2 x 1.0mm, the crystal can help to reduce the size of mobile equipment and modules.
With most crystal units, ESR worsens when the vibrating area of a crystal is restricted. The company reports favourable ESR values by using a special packaging technology and high precision assembly. Normally the package is made low-profile to reduce the size of the crystal unit, but that leads to deformation of the package, and seal breakage. Using a structure that distributes stress at the time of moulding, the company says it assures dielectric strength.
Conforming to RoHS regulations, the 37.4MHz XRCED37M400FXQ52R0 crystal unit is lead free (phase 3) and allows lead-free soldering. The component offers a frequency tolerance of ±20ppm across a range of -30 to 85 degree C. The maximum ESR is 60Ohms and the drive level is 100microW maximum.