- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄378431 > C500 (SIEMENS AG) 8-Bit Microcontroller(8位微控制器) PDF資料下載
參數(shù)資料
| 型號： | C500 |
| 廠商： | SIEMENS AG |
| 元件分類： | 8位微控制器 |
| 英文描述： | 8-Bit Microcontroller(8位微控制器) |
| 中文描述： | 8位微控制器（8位微控制器） |
| 文件頁數(shù)： | 7/55頁 |
| 文件大小： | 495K |
| 代理商： | C500 |
第1頁第2頁第3頁第4頁第5頁第6頁當前第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁
7 of 55
AP242401 04.99
Ceramic Resonator Oscillators of the
C500 / C166 Microcontroller Family
2.3
Difference of the Start-up and Oscillation Behavior
Based on the physical difference between quartz crystals and ceramic resonators there are different
analysis methods necessary.
2.3.1 Quartz Crystal
The main problem to characterize the start-up and oscillation reliability is the drive level dependency
(DLD) of R
1
and the overall tolerance of the oscillator circuitry. During start-up time the drive level
of the oscillation is very small and is increased up to the maximum. During that time the resistance
of the crystal can reach very high values because crystals show resistance dips depending on the
drive level and temperature. This effect is called drive level dependence. The DLD of a quartz
crystal depends on the quality and can alter during production and during the life time of the crystal.
If the resistance dips of the crystal increase in a range where the loop gain of the oscillator is lower
than one, then the oscillation cannot start.
The test for start-up and oscillation reliability is done with the ’negative resistance’ method. ApNote
2420xx describes how to perform this test
2.3.2 Ceramic Resonator
The ceramic resonator shows no DLD of R
1
. Therefore R
1
depends only on variation in production.
The main problem to characterize the start-up and oscillation reliability of a ceramic resonator is the
tendency to irregular oscillation. This so called ’spurious’ oscillation of the ceramic resonator is
based on the ability to oscillate on 3rd overtone without tank. A tank consists of an additional
external capacitance and inductance to suppress the oscillation in fundamental mode.
The impedance shows a maximum at 3rd overtone for a ceramic resonator running at 3rd overtone.
The impedance at fundamental and 5th overtone is smaller than at 3rd overtone. The 3rd overton
response (main response) is larger than the fundamental and 5th one.
Depending on gain and phase of the oscillator circuit (μC, external circuit and parasitics of the PCB)
spurious oscillation can occur. Therefore most of the evaluation effort has to be spent to check the
tendency to spurious oscillation.
Note: Long wiring tends to support spurious oscillation by increasing inductance!
Figure 1 :
2 Terminal Type and 3 Terminal Type Ceramic Resonators
2 Terminal Type
3 Terminal Type
相關PDF資料 |
PDF描述 |
|---|---|
| C501 | 8-Bit CMOS Microcontroller |
| C501 | 8-Bit CMOS Microcontroller |
| C504 | 8-Bit CMOS Microcontroller |
| C505-2RM | 8-Bit CMOS Microcontroller |
| C505C-2RM | 8-Bit CMOS Microcontroller |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| C-500 | 制造商:MISCELLANEOUS 功能描述: 制造商:EGS ELECTRICAL GROUP 功能描述:3/8 IN 2 SCR CONNECTOR |
| C5000 | 制造商:TE Connectivity 功能描述:TRANSFORMER - Tape and Reel |
| C50-0001-031 | 制造商:Harris Corporation 功能描述: |
| C5000322-2 | 制造商:Glenair Inc 功能描述:COMPONENT PART - Bulk |
| C5000AV | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:ASIC |
發(fā)布緊急采購，3分鐘左右您將得到回復。