Reduced acoustic noise from ceramic capacitors

June 27, 2014 // By Graham Prophet
A range of MLCCs from Murata have an extra interposer substrate that reduces acoustic “squealing” noise

The ZRB series of monolithic ceramic capacitors (MLCC) is packaged on an interposer substrate designed specifically to reduce acoustic “squealing” noise typically induced by mechanical vibration of the capacitor. Available in the same size as conventional MLCCs, the ZRB is available in EIA 0402 (1.0 x 0.05 mm) and EIA 0603 (1.6 x 0.8 mm) package formats with working voltages of 6.3, 10, 16 and 25 VDC, With this approach, the ZRB becomes a replacement part to update an end-application design without the need for modification of the PCB layout.

This form of acoustic noise has become of concern for the electronics industry and affects many types of consumer electronics devices such as laptops, tablets and smartphones. The PCB can (mechanically) amplify the audio noise generated by the capacitor, so by using an interposer substrate the MLCC becomes mechanically isolated from the PCB. Reduction in audio noise can be achieved against a traditionally designed MLCC.

The ZRB series is available with capacitance values of 4.7, 10 or 22 µF with X5R temperature characteristics.

Murata Europe