Murata Manufacturing Co. Ltd. has introduced the KCM series of metal terminal type multilayer ceramic capacitors with temperature compensating C0G characteristics for automotive applications and the KRM series of metal terminal type multilayer ceramic capacitors for general-purpose applications.
These products are primarily intended for the LC resonance circuits of wireless power transfer systems for electric vehicle and industrial equipment. Mass production of this product is scheduled to start from August 2019.
Summary of specifications:
- Operating temperature range: -55°C to +125°C
- Rated voltage: 630Vdc
- Capacitance: 15nF to 54nF
- Temperature characteristic: C0G characteristics（0±30ppm/℃）
Wireless power transfer (WPT) technology is being developed and practically applied in fields such as electric vehicles and industrial automated transporters. Wireless power supplies using the magnetic resonance method are attracting attention in these fields as they are resistant to drops in transfer efficiency due to distance.
The magnetic resonance method inserts capacitors to both the power transmission side and power reception side to form a LC resonance circuit. Comparatively high power on the order of several kW to several tens of kW is applied to these resonance capacitors, so low loss, low heat generation, and low capacitance variation due to temperature and voltage are required.
Ceramic materials with low loss and low capacitance variation due to temperature and voltage application were selected for the newly developed metal terminal type multilayer ceramic capacitors with C0G characteristics. The metal pins also use low-loss materials and have been optimized for resonance capacitors.