 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
8N3DV76EG-0000CDI8 Datasheet(PDF) 5 Page - Integrated Device Technology |
|
|
|||||||||||||||||||||||||||||
8N3DV76EG-0000CDI8 Datasheet(HTML) 5 Page - Integrated Device Technology |
|
|
5 / 20 page  IDT8N4QV01GCD REVISION A MARCH 11, 2014 5 ©2014 Integrated Device Technology, Inc. IDT8N4QV01 REV G DATA SHEET QUAD-FREQUENCY PROGRAMMABLE-VCXO Principles of Operation The block diagram consists of the internal 3rd overtone crystal and oscillator which provide the reference clock fXTAL of either 114.285MHz or 100MHz. The PLL includes the FemtoClock NG VCO along with the Pre-divider (P), the feedback divider (M) and the post divider (N). The P, M, and N dividers determine the output frequency based on the fXTAL reference and must be configured correctly for proper operation. The feedback divider is fractional supporting a huge number of output frequencies. The configuration of the feedback divider to integer-only values results in an improved output phase noise characteristics at the expense of the range of output frequencies. In addition, internal registers are used to hold up to four different factory pre-set P, M, and N configuration settings. These default pre-sets are stored in the I2C registers at power-up. Each configuration is selected via the FSEL[1:0] pins and can be read back using the SCLK and SDATA pins. The user may choose to operate the device at an output frequency different than that set by the factory. After power-up, the user may write new P, N and M settings into one or more of the four configuration registers and then use the FSEL[1:0] pins to select the newly programmed configuration. Note that the I2C registers are volatile and a power supply cycle will reload the pre-set factory default conditions. If the user does choose to write a different P, M, and N configuration, it is recommended to write to a configuration which is not currently selected by FSEL[1:0] and then change to that configuration after the I2C transaction has completed. Changing the FSEL[1:0] controls results in an immediate change of the output frequency to the selected register values. The P, M, and N frequency configurations support an output frequency range 15.476MHz to 866.67MHz and 975MHz to 1,300MHz. The devices use the fractional feedback divider with a delta-sigma modulator for noise shaping and robust frequency synthesis capability. The relatively high reference frequency minimizes phase noise generated by frequency multiplication and allows more efficient shaping of noise by the delta-sigma modulator. The output frequency is determined by the 2-bit pre-divider (P), the feedback divider (M) and the 7-bit post divider (N). The feedback divider (M) consists of both a 7-bit integer portion (MINT) and an 18-bit fractional portion (MFRAC) and provides the means for high-resolution frequency generation. The output frequency fOUT is calculated by: f OUT f XTAL 1 PN ------------- MINT MFRAC 0.5 + 2 18 ----------------------------------- + = (1) The four configuration registers for the P, M (MINT & MFRAC) and N dividers which are named Pn, MINTn, MFRACn and Nn with n = 0 to 3. “n” denominates one of the four possible configurations. As identified previously, the configurations of P, M (MINT & MFRAC) and N divider settings are stored the I2C register, and the configuration loaded at power-up is determined by the FSEL[1:0] pins. Input Selects Register FSEL1 FSEL0 0 (def.) 0 (def.) Frequency 0 P0, MINT0, MFRAC0, N0 0 1 Frequency 1 P1, MINT1, MFRAC1, N1 1 0 Frequency 2 P2, MINT2, MFRAC2, N2 1 1 Frequency 3 P3, MINT3, MFRAC3, N3 Frequency Configuration An order code is assigned to each frequency configuration programmed by the factory (default frequencies). For more information on the available default frequencies and order codes, please see the Ordering Information Section in this document. For available order codes, see the FemtoClock NG Ceramic-Package XO and VCXO Ordering Product Information document. For more information and guidelines on programming of the device for custom frequency configurations, the register description, the pull-range programming and the serial interface description, see the FemtoClock NG Ceramic 5x7 Module Programming Guide. Table 4. Frequency Selection |
Similar Part No. - 8N3DV76EG-0000CDI8 |
|
Similar Description - 8N3DV76EG-0000CDI8 |
|
|
|
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 |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
