The frequency signal is as important to all electronic products as the heartbeat is to the life of all animals. All electronic circuits operate with this repetitive and stable frequency signal as the reference signal source. Designing a good frequency signal is almost an important basis for the system to achieve high performance, continuous and stable operation. In general, the reference frequency signal designed by the system can be generated by different frequency components, such as a resonator (Resonator), an oscillator (Oscillator), and a frequency generator (Clock Generator). Different system designs are considered according to different design considerations. Select different components to provide a reference frequency. The resonator uses the principle of mechanical vibration, plus an external resonant circuit to generate a periodic oscillating signal, which is typically integrated into the chip. The oscillator component integrates the resonator and resonant circuit in a 4 or 6-pin package to output a reference frequency signal. The frequency generator is a relatively complex frequency signal output component. Generally, such components require an external reference resonator, and internally integrate one or more phase lock loops (PLLs) to generate one or several references. The signal of the frequency output. For all system designs, no matter which frequency component is used as the reference signal for circuit design, a stable and good quality periodic signal is required, including good waveform, duty cycle, short climb time and fall time ( Rising TIme & falling TIme), as well as accurate repeatable edge times. Innovative MEMS resonator Most of the previous electronic products rely on quartz crystals to provide reliable and stable frequency signals. However, in recent years, electronic components designed and manufactured by MEMS technology have provided innovative and high-quality electronic products in many applications, including MEMS resonance. The components have begun to replace quartz crystals in many applications: for example, resonators used inside so-called MEMS oscillators, that is, millimeter-scale MEMS resonators, as the Mega Hertz-class oscillator source. MEMS oscillator internal design In addition to the MEMS technology of the innovative resonator, the oscillator circuit design inside the oscillator is also in progress. The oscillation circuit inside the conventional quartz oscillator has the same output frequency as the quartz design cutting frequency. Therefore, the circuit design only uses a simple resonant amplifying circuit or a driving circuit. Inside the MEMS oscillator, the new design concept and circuit design enable the MEMS oscillator to provide more configurable variable frequency parameters. Different parameters can be set through the mass production program before shipment, which can provide special application fields. need. MEMS oscillators have begun to gradually replace traditional fixed-frequency or programmable-output quartz oscillators in many applications, including computer peripherals, consumer electronics, Netcom equipment, communications equipment, automotive electronics, and industrial products. This design simplifies the current lengthy supply chain of quartz oscillators, shortens the delivery time of manufacturers, and enables parts using the same circuit design to meet the needs of different designs, and further assists system manufacturers to achieve oscillators with different frequencies and different parameters. The goal of One Stop Shopping. Brief perspective of MEMS oscillator Figure 1 is a perspective view of a MEMS oscillator. Take SiTIme's MEMS oscillator as an example. It consists of two chips stacked up, with a CMOS PLL driver chip on top and a MEMS resonator on top, in a standard QFN IC package. The package size and solder pins are fully compatible with the traditional standard quartz oscillator pins, which can directly replace the original quartz products without any design changes. MEMS oscillators go beyond quartz oscillator products in many ways, including fully automated production processes, stable lead times, consistent product quality, and near- and long-term cost advantages. Figure 1 perspective view of all-silicon MEMS oscillator How to make MEMS resonators? Some manufacturers manufacture all-silicon MEMS resonators using standard equipment and materials from CMOS semiconductor foundries. This eliminates the need for additional equipment and process investments in CMOS semiconductors, which will enhance the CMOS industry's economic niche by using existing equipment to produce more products. In addition, the MEMS oscillator package method also uses the current semiconductor package factory general equipment and standard IC post-production packaging process. Figure 2 shows a cross-sectional view of a series of MEMS fabrications. Figure 2a shows the formation of a resonant structure by cutting a gap from the surface to a silicon oxide insulating layer (SOI) by a narrow channel etch. These resonant structures vibrate in a horizontal direction on the silicon crystal surface during vibration. Figure 2a Schematic diagram of the resonator and electrode generated from the surface of the wafer etched into the oxidized insulating layer As shown in FIG. 2b, the vibration gap is covered with an oxide layer, a silicon crystal layer, and a polysilicon layer, and the polysilicon layer is formed by taking out the oxide through small etching holes to form a resonator. Figure 2b After the oxide layer and the siliceous vent layer are formed, the pores are made to discharge the gas in the space between the internal electrodes of the resonator to form a vacuum. 60V20Ah Lithium Ion Battery,Waterproof Battery Pack For Bicycle,60V 20Ah L-Ion Waterproof Battery,Rechargeable 60V Lifepo4 Lithium Battery Jiangsu Zhitai New Energy Technology Co.,Ltd , https://www.jszhitaienergy.com
