欢迎访问ic37.com |
会员登录 免费注册
发布采购

U3750BM 参数 Datasheet PDF下载

U3750BM图片预览
型号: U3750BM
PDF下载: 下载PDF文件 查看货源
内容描述: 单芯片电话线路 [One Chip Telephone Circuit]
分类和应用: 电信电路电话电路
文件页数/大小: 20 页 / 206 K
品牌: TEMIC [ TEMIC SEMICONDUCTORS ]
 浏览型号U3750BM的Datasheet PDF文件第12页浏览型号U3750BM的Datasheet PDF文件第13页浏览型号U3750BM的Datasheet PDF文件第14页浏览型号U3750BM的Datasheet PDF文件第15页浏览型号U3750BM的Datasheet PDF文件第17页浏览型号U3750BM的Datasheet PDF文件第18页浏览型号U3750BM的Datasheet PDF文件第19页浏览型号U3750BM的Datasheet PDF文件第20页  
U3750BM  
TELEFUNKEN Semiconductors  
Dialer  
The IC includes a dialing circuit for either pulse dialing on the dialing. The code A is filtered and corresponds to  
or dual tone multifrequency dialing. The dialer transmits eleven pulses.  
the codes decoded by the logic keyboard on the outputs  
OL and MF.  
Dialing  
As soon as the code is detected by the logic keyboard and  
written in RAM, it can only be loaded in the dialer if the  
dialer is not occupied and a pause is not generated.  
Mode Selection  
The choice of dialing is made by the tri-state-level on the  
DC/FV Pin  
Pulse Dialing  
FV DC = Z  
FV DC  
pulse dialing in 66/33 ms  
The output which provides control signals for proper  
timing in pulse dialing is pin, OL. The dialling starts with  
a make time (see figure 12).  
tied to pin RESET pulse dialing in 60/40 ms  
FV DC = 0 DTMF dialing calibrated  
When the circuit is in pulse mode, it is possible to change  
over to DTMF dialing with the *” key. The code *” is  
sent in line. The circuit returns in pulse mode after a reset  
condition or after a flash pulse (see figure 14).  
Dual tone Multifrequency Dialing  
The output pin, MF, provides the multifrequency signal  
to transmit in line. This signal results from the sum of two  
frequency pulses modulated and requires a filter to com-  
pose a dual sine wave. The frequencies are chosen in a low  
Dialing Codes  
The dialing codes are the numeric keys 0 to 9, and the non group and a high group. Table 3 shows the frequency  
numeric keys A, B, C, D, *, #. All are stored in RAM. The tolerance of the output tones for DTMF signalling. In  
codes A, B, C and D can be only transmitted by the serial manual dialing or in redial, output tone is timed with a  
bus. In pulse dialing, the code #, B, C and D have no effect fixed duration.  
Table 4 Frequency tolerance of the output tones for DTMF signaling  
Standard  
Frequency  
Tone Output  
Frequency  
Frequency Deviation  
Hz  
Hz  
%
Hz  
Low Group  
697  
697.8  
768.6  
848.9  
940.1  
+0.12  
–0.18  
–0.37  
–0.10  
+0.85  
–1.42  
–3.12  
–0.92  
770  
852  
941  
High Group  
1209  
1210.1  
1338.2  
1477.3  
1636.7  
+0.09  
+0.17  
+0.02  
+0.22  
+1.11  
+2.23  
+0.27  
+3.69  
1336  
1477  
1633  
Tone output frequency when using a 455 kHz ceramic.  
16 (20)  
Rev. A1: 16.07.1996