参数资料
型号: MK2049-02SI
元件分类: 时钟产生/分配
英文描述: 51.84 MHz, OTHER CLOCK GENERATOR, PDSO20
封装: 0.300 INCH, SOIC-20
文件页数: 11/11页
文件大小: 136K
代理商: MK2049-02SI
MK2049-02/03
Communications Clock PLLs
MDS 2049-02/03 C
9
Revision 091801
Integrated Circuit Systems, Inc. 525 Race Street San Jose CA 95126 (408)295-9800tel www.icst.com
External Components Selection
CAP2
CAP1
0.015
F
470 k
0.1 F
Crystal Operation
Figure 4. Loop Filter Component Values
Typical component values are shown. Contact the ICS applications department at
(408)297-1201 for the recommended values for your application.
The MK2049 operates by phase locking the input signal to a VCXO which consists of the special recommended
crystal and the integrated VCXO oscillator circuit on the MK2049. To achieve the best performance and reliability, the
layout guidelines shown on the previous page must be closely followed.
The frequency of oscillation of a quartz crystal is determined by its cut and by the load capacitors connected to it. The
MK2049 has variable load capacitors on-chip which “pull”, or change the frequency of the crystal. External stray
capacitance must be kept to a minimum to ensure maximum pullability of the crystal. To achieve this, the layout should
use short traces between the MK2049 and the crystal.
For the VCXO to operate correctly, a crystal properly specified and matched to the MK2049-02/03 must be used. For
more information, including a list of recommended crystals, refer to application note MAN05.
The external loop filter should be connected between CAP1 and CAP2 as shown in Figure 4 below, and as close to
the chip as possible. High quality ceramic capacitors are recommended. DO NOT use any type of polarized or
electrolytic capacitor. Ceramic capacitors should have C0G or NP0 dielectric. Another alternative is the Panasonic
PPS polymer dielectric series; their part number for the 0.1 F cap is ECHU1C104JB5. Avoid high-K dielectrics like
Z5U and X7R; these and other ceramics which have piezolectric properties allow mechanical vibration in the system
to increase the output jitter because the mechanical energy is converted directly to voltage noise on the VCO input.
LAYOUT AND EXTERNAL COMPONENTS (continued)
相关PDF资料
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相关代理商/技术参数
参数描述
MK2049-02SITR 制造商:ICS 制造商全称:ICS 功能描述:Communications Clock PLLs
MK2049-02STR 制造商:ICS 制造商全称:ICS 功能描述:Communications Clock PLLs
MK2049-03S 制造商:MICROCLOCK 功能描述:
MK2049-03SI 制造商:ICS 制造商全称:ICS 功能描述:Communications Clock PLLs
MK2049-03SITR 制造商:ICS 制造商全称:ICS 功能描述:Communications Clock PLLs