飛思卡爾輪胎壓力監(jiān)控系統(tǒng)(TPMS) 在線座談問(wèn)題解答(11)
[ 問(wèn)題 86 ] 請(qǐng)介紹一下在TPMS系統(tǒng)中聲表面波（SAW）器件的應(yīng)用前景！謝謝！
[ 答案 86 ] Freescale solution does not include SAW.
[ 問(wèn)題 87 ] 如果我公司希望直接集成貴公司現(xiàn)有的demo模塊是否可行，比如直接從串口讀取所需數(shù)據(jù)？另外demo模塊的PCB圖和源代碼能否開(kāi)放？
[ 答案 87 ] The demo is include source code. But you the code does not allow you integrate directly. It only allow you review the code and understand how it programed. If you read the data directly, you may see some error as its designed so.
[ 問(wèn)題 88 ] 為什么hc908rf2發(fā)送和MC33594接收所使用的晶振頻率不一樣,必須使用AN1951.PDF所推薦的晶振(為13.56和13.580625)么?
[ 答案 88 ] 請(qǐng)看他們的數(shù)據(jù)手冊(cè)，PLL分頻器的不同比例決定的。
[ 問(wèn)題 89 ] 如何保證整機(jī)的低功耗和抗干擾性？
[ 答案 89 ] All this depends on the algorithm used. You need to decide on saving battery life in driving and parking mode. Some countries do not make transmissiom in park mode whilst others do so once every 30mins. For anti-jamming, the Tire 32 bit IDs allows designed
[ 問(wèn)題 90 ] 輪胎壓力監(jiān)控系統(tǒng)(TPMS)和飛思卡爾TPMS解決方案的成本怎樣？
[ 答案 90 ] Please inquire price through Freescale local sales office or distributor. The cost depent on the production year and purchasing quantity.
[ 問(wèn)題 91 ] 請(qǐng)問(wèn)方案的功耗是多少，RF接收和發(fā)送的功耗，安裝位置在什么地方，通信距離是多少，輪胎溫度超過(guò)85度時(shí)，方案怎么解決，謝謝
[ 答案 91 ] System power consumption depend on your system design, like how many min. you read and transmit signal. transmition distance depend on you antina design and tyre condition. MPXY8020A and 908RF2MFA operation temp up to +125C
[ 問(wèn)題 92 ] 我想了解一下RF芯片的功放如何實(shí)現(xiàn)?有哪些常用芯片?
[ 答案 92 ] 請(qǐng)參考Application note AN2719
[ 問(wèn)題 93 ] TPMS的接收靈敏度有多高?如何防止汽車(chē)EMI的干擾?
[ 答案 93 ] 接收靈敏度有-90dBm今天討論的方案在防止汽車(chē)EMI的干擾,在前面的問(wèn)題己答.主要是用短傅輸時(shí)間和ID來(lái)做.
[ 問(wèn)題 94 ] 我們采用貴公司的MPXY8020A和68HC908RF2方案做了個(gè)TPMS，在常溫常壓下溫度值是00H~03H，壓力值在60H附近。我的仿真軟件用的是P＆E Micro 的ics08rkz.請(qǐng)問(wèn)您能否幫我查找一下原因？？謝謝了�。�！
[ 答案 94 ] 檢查您的測(cè)量方式，軟件方面注意流程，可以參考我們的評(píng)估板這部分軟件，和8020A的測(cè)量方式。在常溫和常壓下，應(yīng)該測(cè)量到100KPa附近和25C左右的數(shù)值。
[ 問(wèn)題 95 ] 為什么用電容式壓力傳感器，為什么不用應(yīng)變片或壓阻式？
[ 答案 95 ] PZ resistive can also work but it is more costly in power. Capacitive is leading technology in this respect and you need to have many years of running power for tires.
