Only by adopting completely different ideas, technologies and processes can we bring about a subversive technological revolution, which is an effect that cannot be achieved by tinkering. Because the realization principle of MEMS oscillator is completely different from the previous Shi Ying crystal oscillator, it can overcome many inherent disadvantages of the existing Shi Ying crystal oscillator. The specific summary is as follows: (The information comes from official website, the first-class agent manufacturer of SITIME)
Advantages brought by adopting all-silicon MEMS technology
1. Volume advantages
The oscillation frequency of Shi Ying crystal oscillator is limited by the volume of Shi Ying crystal, and it is very difficult to cut Shi Ying crystal with tiny volume. The smaller the volume of Shi Ying crystal, the lower its manufacturing yield and the worse its impact resistance. MEMS oscillators can be easily miniaturized.
At present, SiTime's MEMS oscillator has been able to achieve a package volume of 252, but it is difficult for Shi Ying crystal to achieve such a small volume. According to Jeff, the product marketing director of SiTime Company, "The next step is to realize the MEMS oscillator packaged in 216." In addition to smaller and smaller electronic devices that need the cooperation of smaller volume oscillators, some of the latest electronic devices are even so small that the traditional Shi Ying crystal oscillator cannot meet the requirements. For example, the next-generation high-capacity SIM card (HC-SIM) needs an external clock because it needs a USB interface. However, the thickness of the HC SIM card is very limited, only .7 mm, and it is difficult for the traditional Shi Ying crystal oscillator to be less than 1 mm. At this time, the SiT83XT with a thickness of only .25 mm will be the best solution.
2. Advantages of stability
After using 2M-33MHrs, the performance stability of traditional crystal oscillator will decrease, while the time for MEMS oscillator to appear this problem is 5MHrs, and the stability is improved by more than ten times.
in addition, the simulation coefficient of MEMS oscillator can reach-5, g, while the traditional Shi Ying crystal oscillator can only reach-2, g, due to the stable package patented by SiTime. Therefore, compared with the fragile Shi Ying crystal oscillator, the MEMS crystal oscillator is much stronger.
3. Performance advantages
MEMS crystal oscillator can achieve lower power consumption and faster start-up time. The power consumption can be as low as 3.5 mA, and the startup speed can be as fast as 3 milliseconds. This can help to meet the low power consumption requirements of existing portable products.
MEMS oscillator can achieve an accuracy of 1 PPM, which is difficult for Shi Ying crystal oscillator. The highest accuracy of existing Shi Ying crystal oscillator is 25-3PPM. Higher precision provides redundancy for designers to design products.
4. Consistency advantage of quality
MEMS oscillator adopts all-silicon technology, which is completely produced according to the manufacturing technology of semiconductor IC, and can adopt mature and stable semiconductor technology, so its quality stability is higher. Shi Ying crystal oscillators with different frequencies have to adopt different cutting production lines, which will finally affect the quality and stability of products.
5. Cost advantage
MEMS adopts all-silicon technology, which can be manufactured in any wafer factory in the world, and the huge number of products will not affect the product cost. In the case of Shi Ying Crystal Oscillator, if the manufacturer wants to meet the product quantity demand beyond the current production capacity, it needs to purchase more equipment to build more production lines. The increase of labor cost and equipment cost will directly affect the product cost, and the use of new equipment and new workers will even affect the stability of product quality.
Advantages brought by the adoption of programmable technology
1. The delivery cycle is greatly shortened
Due to the adoption of programmable technology, products with different frequencies can be provided in a short time according to the different frequency needs of customers, with an average delivery period of two weeks, while the usual delivery cycle of Shi Ying Crystal Oscillator is eighteen weeks. This is very important today when manufacturers are more and more sensitive to the time to market and the product life cycle is getting shorter and shorter.
David, vice president of Asia-Pacific sales of SiTime, said that in order to meet the needs of a customer in the United States, Sitime provided samples within 24 hours, 1 products within one week, and achieved mass supply to meet the needs of customers within two weeks.
2. Reduce the number of suppliers and verification time
With the traditional Shi Ying crystal oscillator, no manufacturer can guarantee to provide all the frequencies required by customers. Therefore, manufacturers need to choose products from multiple crystal oscillator manufacturers, and in order to ensure the reliability of products, crystal oscillators with different frequencies need to be verified.
with MEMS oscillators, because the frequency is programmable, only a limited number of oscillators from one manufacturer can meet the needs of manufacturers for oscillators with different frequencies. Dealing with as few suppliers as possible and spending as little time as possible on product verification are helpful for manufacturers to reduce costs, simplify manufacturing processes and speed up the time to market.
3. Help manufacturers to solve EMI problems
Although designers do a lot of consideration on EMI/EMC problems in the initial stage of design, they often encounter the problem that they cannot be mass-produced when the final design is completed because they fail the EMI test. The traditional solutions are as follows:
1. Re-optimize the layout, which takes the longest time and costs the most. 2. Add shields and filters to the corresponding positions, which will increase the cost and manufacturing difficulty. 3. With the MEMS spread-spectrum oscillator, there is another way to solve the EMI problem caused by the clock by using the spread-spectrum oscillator. Different spread modes and spread amplitudes can achieve different effects, and the best case is to reduce EMI by 12 dB. In practical application, designers have used MEMS spread spectrum clock instead of the original Shi Ying crystal oscillator to make the products that failed the EMI test pass smoothly.
other advantages:
and the existing Shi Ying crystal PIN-TO-PIN can be replaced smoothly.
various voltages ranging from 1.8V to 3.3V can be used to fully cover the output voltage specifications of existing electronic products.
with differential output function. The oscillation frequency is high, and the highest oscillation frequency can be 8M, which meets the needs of high-end applications such as communication.
due to the above performance advantages, MEMS oscillator will replace the existing Shi Ying crystal oscillator in the long run. However, because oscillators have the characteristics of low price, large consumption and important functions in use, many manufacturers
have their own usage habits and regular customers. To replace Shi Ying crystal oscillator with MEMS crystal oscillator, there are also the following problems to be solved:
Expanding the awareness of MEMS oscillator in the industry
Cultivating customers' usage habits
Expanding the price advantage of Shi Ying crystal oscillator, which is only equivalent at present.