The ceramic inductor adopts laminated monolithic structure, which has the characteristics of high reliability, high self resonance frequency, high Q value and so on. As an international leader in magnetic devices, relying on its own powerful automation technology, production capacity, good product consistency. The product can be used in many communications and electronic equipment, such as RF lines. In general, ceramic inductors play a role in RF circuits:
RF circuit impedance matching (RF impedance match)
Radio frequency resonance (RF resonance)
The RF power supply line choke (RF choke)
RF filtering and isolation (RF filtering and isolation)
Ceramic inductor specific applications
Electronic mass production of ceramic inductors are classified as follows:
SDCL (01005~0603 inch) series: multilayer ceramic inductors, loop suitable for high frequency, such as RF communications equipment, frequency selective circuit etc..
SDWL-C (0402~1812 inch) series: wire wound ceramic inductor with high precision, high S.R.F, high rated current and other characteristics, the price is relatively high, so it is usually applied to the high performance requirements, or positioning high-end products.
HQ (0402~0603 inch) series: laminated ceramic inductors, but with a high S.R.F and high Q value, with the winding ceramic SDWL-C series performance.
Table 1 the correlation between inductance and application of ceramics Note: * the number represents a strong correlation / represent independent; the inductance: consistent application frequency; the frequency of the application: Q; #: self resonance frequency consistency.
Table 2 common inductance type or inductance recommended Ceramic inductor applications
1, the problem: the application of line loss, low sensitivity, poor rate of less than 1%
The essential reason may be due to improper selection of inductance (capacitance) in the matching circuit. In particular, the inductance (capacitance) is not the optimal value when the inductance (capacitance) is applied to the motherboard, which results in poor matching. May lead to poor analysis of the above matching:
(1) different manufacturers have the same nominal value of the product in the application of the frequency of the inductance is biased, direct replacement lead to bad;
(2) the initial selection is poor, and the optimal inductance value is not selected;
(3) inductance polarity, different directions of the performance of the inductance of the bias caused by poor matching;
Solution: in accordance with the new series of products for debugging, the application of the optimal value of the corresponding inductance model; inductance polarity caused by the bad match, you can use the direction of the Mark with the inductance adjustment.
2, the problem: the application of low sensitivity, poor rate of 100%
Analysis of possible causes: low inductance Q value in application frequency. With the adoption of the function of the communication products such as multi-mode, it is urgent to require the high performance of the inductors in the circuit of these products, especially the inductor has higher Q value. In the ANT peripheral circuit and SAW filter matching, the use of high Q inductor can improve the sensitivity and reduce the transmission loss. In addition, the high Q of the VCO oscillator coil can stabilize the oscillation signal and increase the C/N ratio, which is related to the improvement of the quality of wireless communication. Solution: SDWL-C series of ceramic wire wound inductors or HQ series, such as high Q inductance.
3, the problem: the application of inductive circuit is not conductive, defective rate of less than 1%
The possible reasons: the inductance inductance circuit or weld or welding deviation. The reasons for the inductance open circuit are analyzed as follows:
(1) in a continuous inductance excessive current through the inductor electrode burned off, such as inductance rated current audio amplifier circuit is smaller than the operating current and open circuit; solution: the use of lower RDC products, when necessary, using larger inductance.
(2) the inductance pulse current through the inductor electrode burned off, such as inductive key circuit in suffered the impact of ESD open; solutions: Design of ESD protection circuit, or use less RDC products, when necessary, using larger inductance.
(3) the inductance is on the edge of the main board, and when the plate is too large, the inductive electrode is cut off. The solution is to reasonably arrange the position and direction of the inductance on the PCB and reduce the stress of the plate.