GPS Module Selection __MTK

Research and development of GPS products is the choice of GPS module or chip scheme. The market above the GPS program, how to choose it. I have been in contact with GPS design for several years, and now the experience of GPS project selection summarized as follows:

First, the GPS module program, to regional division, Europe and the United States, Taiwan, Korea, * *. If from the stability, engineering services, Europe and the United States relatively better, Taiwan South Korea, * * Do the GPS module is now mainly the stability and consistency of the problem. Some friends may say that the engineering services in Europe and the United States are not too good, may be due to the time lag back longer, but if the quality above is still dominant. Module scheme design, EMI/CMC relatively low requirements, because these GPS modules in the factory has done a number of full inspection, EMI/CMC have been strictly tested, so only pay attention to the surrounding circuit there is no problem, of course, if the quantity of small requirements of high quality, you can also choose the line of PCBA, Directly with the standard protocol through the UART serial connection can be.

Second, the GPS chip scheme, now the market top chip scheme a lot, sirf,u-nav,mtk,m-star and so on. Now it seems that the cost of the chip scheme is lower. But the design of the chip scheme will take quite a long time, the general technical strength of the better will take 6-12 months to make a mature scheme, so this scheme, generally require a large quantity, design strength, low performance requirements, will consider the adoption. GPS selection not only to consider the cost of GPs itself, but also to consider the hidden costs, usually consider the following issues: A. BOM cost, commonly understood cost; B. Project preparation & start-up costs C. Evaluation cost of each GPS product; d. Variable cost, usually have inventory, bad rate, raw material depreciation, quality insurance, production and other costs; E. Delay in the cost of listing; F. Continuation of development costs, GPS chip scheme if the revision, flexibility is very poor, because GPS is a system, if the revision must be redesigned.

Third, software GPS program, need more powerful CPU, generally need more than 600MHz, with the development of technology, CPU frequency in more than 800MHz more and more. Software GPS, as the CPU becomes more and more powerful, will gradually become a trend. Because the CPU has more correlator resources, so Finnish Fastrax VP Kim Kaisti said, Software GPS performance Development to -163dbhz there is room. This performance has exceeded most of the market performance of the GPS module, low prices, but generally need to software GPS for the manufacturer should be directly with the CPU, need more technical support. The use of SW GPs also to consider power consumption, Software GPS general power consumption is larger.