德爾福全英筆試題目

　　德爾福集團(tuán)是全球最大的汽車系統(tǒng)和零部件生產(chǎn)制造商, 為客戶提供品種齊全的汽車系統(tǒng), 零部件和模塊。今天成電的就業(yè)辦老師介紹說，德爾福是汽車界的華為，從來不在媒體上打廣告。大家看看從美國空運(yùn)過來的筆試題目。

　　1、name 3 vehicle buses.

　　2、name 2 possible sources of electromagnetic interference on electronics circuit asm.

　　3、wavelength for 12mhz frequency signal is____

　　4、name 2 important considerations for car radio performance related to audio　signal processing under multipath condition?

　　5、what is the typical fm receiver rf signal strength to achieve 30db s/n for　car radio?

　　6、when a radio is tuned to 98.1 mhz & with a lo of 108.8 mhz, what is the image frequency?

　　7、for a system with a matched impedance, what is the reflection coefficient and swr?

　　8、which property of the output capacitor is the primary cause of low drop out　(ldo) regulator loop instability?

　　a) equivalent series resistance(esr)

　　b) effective series inductance(esl)

　　c) capacitance value

　　d) dielectric material

　　9、the switching regulator is capable of:

　　a) higher power conversion efficiency

　　b) providing an output voltage that is higher than the input

　　c) generating an output boltage oppsite in polarity to the input

　　d) all of the above

　　10、a linear regulator op＊(沒抄清楚)

　　vin(max)=10v,vout(min)=4.8v,iout(max)=2.5ma,iq(max)=2.5ma,ta(max)=8.5攝氏度，the regulator is available in 3 packages.each package has the following thermal characteristics:

　　package rja(攝食度/w) rjc(攝食度/w)

　　to220 50 35

　　so14 125 30

　　d1p8 100 52

　　choose the most suitable package to handle the power dissipation requirement without a heat sink and why.