欢迎访问ic37.com |
会员登录 免费注册
发布采购

RX5C348A 参数 Datasheet PDF下载

RX5C348A图片预览
型号: RX5C348A
PDF下载: 下载PDF文件 查看货源
内容描述: 4线串行接口 [4-WIRE SERIAL INTERFACE]
分类和应用:
文件页数/大小: 45 页 / 1293 K
品牌: RICOH [ RICOH ELECTRONICS DEVICES DIVISION ]
 浏览型号RX5C348A的Datasheet PDF文件第23页浏览型号RX5C348A的Datasheet PDF文件第24页浏览型号RX5C348A的Datasheet PDF文件第25页浏览型号RX5C348A的Datasheet PDF文件第26页浏览型号RX5C348A的Datasheet PDF文件第28页浏览型号RX5C348A的Datasheet PDF文件第29页浏览型号RX5C348A的Datasheet PDF文件第30页浏览型号RX5C348A的Datasheet PDF文件第31页  
Rx5C348A/B  
Configuration of Oscillation Circuit and Correction of Time Count Deviations  
Configuration of Oscillation Circuit  
Typical externally-equipped element  
X’tal : 32.768kHz  
VDD  
VDD  
(R1=30ktyp)  
OSCIN  
(CL=6pF to 8pF)  
RF  
CG  
RD  
Standard values of internal elements  
32kHz  
RF  
RD  
15Mtyp  
120ktyp  
OSCOUT  
A
CD  
CG,CD 12pF typ  
The oscillation circuit is driven at a constant voltage of approximately 1.2v relative to the level of the VSS pin  
input. As such, it is configured to generate an oscillating waveform with a peak-to-peak voltage on the order of  
1.2v on the positive side of the VSS pin input.  
< Considerations in Handling Crystal Oscillators >  
Generally, crystal oscillators have basic characteristics including an equivalent series resistance (R1) indicating  
the ease of their oscillation and a load capacitance (CL) indicating the degree of their center frequency.  
Particularly, crystal oscillators intended for use in the Rx5C348A/B are recommended to have a typical R1 value  
of 30kand a typical CL value of 6 to 8pF. To confirm these recommended values, contact the manufacturers  
of crystal oscillators intended for use in these particular models.  
< Considerations in Installing Components around the Oscillation Circuit >  
1) Install the crystal oscillator in the closest possible vicinity to the real-time clock ICs.  
2) Avoid laying any signal lines or power lines in the vicinity of the oscillation circuit (particularly in the area  
marked "A" in the above figure).  
3) Apply the highest possible insulation resistance between the OSCIN and OSCOUT pins and the printed circuit  
board.  
4) Avoid using any long parallel lines to wire the OSCIN and OSCOUT pins.  
5) Take extreme care not to cause condensation, which leads to various problems such as oscillation halt.  
< Other Relevant Considerations >  
1) For external input of 32.768-kHz clock pulses to the OSCIN pin:  
DC coupling: Prohibited due to an input level mismatch.  
AC coupling: Permissible except that the oscillation halt sensing circuit does not guarantee perfect operation  
because it may cause sensing errors due to such factors as noise.  
2) To maintain stable characteristics of the crystal oscillator, avoid driving any other IC through 32.768-kHz clock  
pulses output from the OSCOUT pin.  
12345  
Rev.2.01  
- 27 -  
 复制成功!