With the continuous research and development of high-tech, various equipments have entered the high-end, as a reserve army, the power circuit has also made significant progress. Specifically, in the case of a typical mobile phone, in addition to the original call function, various functions such as a camera, a broadcast, and a television have become a universal standard function. The voltages required for the operation of these functions are different. To this end, the battery voltage must be converted by the power conversion circuit to the voltage required for the normal operation of each circuit. Switching controllers (often referred to as DC-DC converters) with high power conversion efficiency are mostly used.
In addition, in the process of multi-functionalization of mobile devices, the requirements for small and thinner machines are gradually increasing. To do this, you must reduce the number of components used, or make the components smaller. This countermeasure is to adapt to the miniaturization of components by increasing the switching frequency of the DC-DC converter and reducing the necessary power inductor and capacitor rating parameters. The switching frequency of the PMIC (PowerManagementIC) that will centrally control the power supply will be changed from 1 MHz to 3 MHz, and the mainstream frequency of the DC-DC converter IC that manages the separate power supply is always 3 to 4 MHz. The power inductors of the main components require low-sensitivity products from 1.0uH to 2.2uH. The increase in the number of switching frequencies makes squelch necessary, and in order to solve these problems, the development of power inductors has been promoted.
Necessary characteristics of power inductors in mobile phone power circuits
Here, the requirements of the shape and characteristics of the power inductor of the power supply circuit of the multifunctional small mobile phone are described. There are three main items.
• Small size and thin thickness
• Has the ability to adapt to the high power conversion efficiency of the power circuit
• Anti-noise capability under power supply operation
Next, the performance of the power inductor developed by Murata Manufacturing Co., Ltd. with the above performance will be explained.
Stacked power inductors developed for small power circuits
Corresponding to small and thin power inductors and their main performance
Murata Manufacturing Co., Ltd. has developed a series of power inductors LQM2HP (2520 size) and LQM2MP (2016 size) for power supply circuit miniaturization, and put them into mass production. These power inductors are ultra-thin designs that meet the 1.0mm thick package trend of baseband ICs such as PMICs and power supply terminals. The shape is shown in Figure 1.
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Twinkle System Technology Co Ltd , https://www.pickingbylight.com