Knowles is saving space in power supply PCBs by offering edge-stacked ceramic capacitor assemblies.

Knowles-SV-Series-NF-Group

Intended for filtering in the input and output stages of switch-mode PSUs,  the parts are the ‘SV’ series.

“The assemblies can be made with up to 10 chips of the same size with various lead configurations to safeguard against thermal and mechanical stresses,” according to product manager Dan Callen. “SV series is 100% tested for dielectric withstanding voltage, insulation resistance, capacitance and dissipation factor.”

X7R dielectric is used and values of 14, 22, 27, 47, 68, 100 and 220μF are available, at 100, 50 or 25V. Not all combinations are available – there are nine versions in all, essentially a 3-stack, a 5-stack and a 10-stack at each voltage.

Parts range in length from 9.5 to 27.3mm, and there are bend lead (pictured) and straight lead versions.

ESR (series resistance) is well below 100mΩ at 1kHz for all parts, and can be as low as 100μΩ at 400kHz. “Low ESR and ESL are inherent in the SV series design, which gives the assemblies the capability to handle high ripple currents at high frequencies,” according to Knowles. “Since ripple current can cause self-heating through I2R losses and degradation in a capacitor, reducing ESR helps minimise these impacts, resulting in less power loss and improved reliability.”

Knowles, through its subsidiary Knowles Precision Devices, produces Dielectric Laboratories, Compex, Johanson, Novacap, Syfer and Voltronics capacitors.