參數(shù)資料
型號: UCB1200
廠商: NXP Semiconductors N.V.
英文描述: Advanced modem/audio analog front-end
中文描述: 先進的調制解調器/音頻模擬前端
文件頁數(shù): 34/54頁
文件大?。?/td> 1052K
代理商: UCB1200
1998 Jul 22
34
Philips Semiconductors
Product specification
Advanced modem/audio analog front-end
UCB1200
APPLICATION INFORMATION
In this chapter some application information is contained. More information will be available when an Application Note
on UCB1200 is published.
Sidetone suppression circuit
An important built-in feature of the telecom codec is the sidetone suppression circuit. The sidetone suppression circuit is
activated when TEL_SIDE_ENA in the telecom control register B is set. The telecom input signal contains a large part
of the telecom output signal, when the sidetone suppression circuit is disabled. The available dynamic range of the
telecom input is occupied largely by the telecom output voltage.
The sidetone suppression circuit subtracts a part of the telecom output signal from the telecom input signal when
activated. The available dynamic range is in that case used more effectively than without sidetone suppression.
The built in side tone suppression circuit, shown in Fig.30, has a fixed subtraction ratio, set be the resistors R
s
and R
i
,
which equals 600/456. This ratio is calculated from the following relations.
The impedance seen by the telephone line equals:
R
,
in which Rt represents winding resistance of the transformer, divided by 2. Assuming Ri >> Ro then
R
line
R
t
R
t
R
o
600 2
300
=
=
+
+
=
Fig.30 Typical telecom codec sidetone suppression circuit (without protection circuits).
-
+
Rs
TOUTP
TINP
11
15
Ri
Rg
R
Rt
-
+
Rs
TOUTN
TINN
12
14
Ri
Rg
R
Rt
Rt
Rt
1:1 transformer
A
B
UCB1200
Z
line
2
R
t
R
t
R
i
R
×
+
R
+
+
×
=
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相關代理商/技術參數(shù)
參數(shù)描述
UCB1200B 制造商:未知廠家 制造商全稱:未知廠家 功能描述:UCB1200B
UCB1200BE 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Advanced modem/audio analog front-end
UCB1300 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Advanced modem/audio analog front-end
UCB1300BE 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Advanced modem/audio analog front-end
UCB1400 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Audio codec with touch screen controller and power management monitor