 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
EM78P447NAM Datasheet(PDF) 26 Page - ELAN Microelectronics Corp |
|
||||||||||||||||||||||||||||||
EM78P447NAM Datasheet(HTML) 26 Page - ELAN Microelectronics Corp |
|
|
26 / 57 page  EM78P447N OTP ROM Table 9 Capacitor Selection Guide for Crystal Oscillator or Ceramic Resonator Oscillator Type Frequency Mode Frequency C1(pF) C2(pF) 455 kHz 100~150 100~150 2.0 MHz 20~40 20~40 Ceramic Resonators HXT 4.0 MHz 10~30 10~30 32.768kHz 25 15 100KHz 25 25 LXT 200KHz 25 25 455KHz 20~40 20~150 1.0MHz 15~30 15~30 2.0MHz 15 15 Crystal Oscillator HXT 4.0MHz 15 15 3. External RC Oscillator Mode For some applications that do not need a very precise timing calculation, the RC oscillator (Fig. 15) offers a lot of cost savings. Nevertheless, it should be noted that the frequency of the RC oscillator is influenced by the supply voltage, the values of the resistor (Rext), the capacitor (Cext), and even by the operation temperature. Moreover, the frequency also changes slightly from one chip to another due to the manufacturing process variation. In order to maintain a stable system frequency, the values of the Cext should not be less than 20pF, and that the value of Rext should not be greater than 1 M ohm. If they cannot be kept in this range, the frequency is easily affected by noise, humidity, and leakage. The smaller the Rext in the RC oscillator, the faster its frequency will be. On the contrary, for very low Rext values, for instance, 1 K Ω, the oscillator becomes unstable because the NMOS cannot discharge the current of the capacitance correctly. Based on the above reasons, it must be kept in mind that all of the supply voltage, the operation temperature, the components of the RC oscillator, the package types, the way the PCB is layout, will affect the system frequency. This specification is subject to change without prior notice. 10.21.2004 (V1.0) 26 |
Similar Part No. - EM78P447NAM |
|
Similar Description - EM78P447NAM |
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.NET |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
