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参数资料
| 型号： | TS34119 |
| 厂商： | Taiwan Semiconductor Co., Ltd. |
| 元件分类： | 运动控制电子 |
| 英文描述： | Low Power Audio Amplifier |
| 中文描述： | 低功率音频放大器 |
| 文件页数： | 5/11页 |
| 文件大小： | 492K |
| 代理商： | TS34119 |
TS34119
5-11
2004/09 rev. A
Design Guideline
GENERAL
The TS34119 is a low power audio amplifier capable of low voltage operation (Vcc=2.0V minimum) such as that
encountered in line-powered speakerphones. The circuit provides a differential output (VO1-VO2) to the speaker to
maximize the available voltage swing at low voltages. The different gain is set by two external resistors. Pins FC1
and FC2 allow controlling the amount of power supply and noise rejection, as well as providing alternate inputs to the
amplifiers. The CD pin permits powering down the IC for muting purposes and to conserve power.
AMPLIFIERS
Referring to the block diagram, the internal configuration consists of two identical operational amplifiers. Amplifier #1
has an open loop gain of
≥
80Db (at f
≤
100Hz), and the closed loop gain is set by external resistor Rf and Rj. The
amplifier is unity gain stable, and has a unity gain frequency of approximately 1.5MHz. In order to adequately cover
the telephone voice band (300Hz to 3.4kHz), a maximum closed loop gain of 46dB is recommended. Amplifier #2 is
internally set to gain of –1.0 (0dB). The outputs of both amplifiers are capable of souring and sinking a peak current
of 200mA.The outputs can typically swing to within
≈
0.4V above ground, and to within
≈
1.3V below V
CC
, at the
maximum current. See Figure 18 and 19 for V
OH
and V
OL
curves.
The output dc offset voltage (VO1-VO2) is primarily a function of the feedback resistor (Rf), and secondarily due to
the amplifiers’ input offset voltages. The input offset voltage of the two amplifiers will generally be similar for a
particular IC, and therefore nearly cancel each other at the outputs. Amplifier #1’s bias current, however, flows out of
Vin (pin 4) and through Rf, forcing VO1 to shift negative by an amount equal to (Rf
×
I
IB
), Vo2 is shifted posited an
equal amount. The output offset voltage, specified in the Electrical Characteristics is measured with the feedback the
feedback resistor shown in the Typical Application Circuit, and therefore takes into account the bias current as wells
internal offset voltages of the amplifiers. The bias current is constant with respect to V
CC
.
FC1 AND FC2
Power supply rejection is provided by the capacitors (C1 and C2 in the typical Application Circuit) at FC1 and FC2.
C2 is somewhat dominant at low frequencies, while C1 is dominant at high frequencies, as shown in the graphs of
Figure 4 to 7. The required values of C1 and C2 depend on the conditions of each application. A line powered
speakerphone, for example, will require more filtering than a circuit powered by a well regulated power supply. The
amount of rejection is function of the capacitors, and the equivalent impedance looking into FC1 and FC2 (listed in
the Electrical Characteristics as R
FC1
and R
FC2
). In addition to providing filtering, C1 and C2 also affect the turn-on
time of the circuit at power-up, since the two capacitors must charge up through the internal 50K and 125K resistors.
The graph of Figure 1 indicates the turn-on time upon application of V
CC
of +6V. The turn-on time is
≈
60% longer for
V
CC
=3V, and
≈
20% less for V
CC
=9V. Turn-off time is <10uS upon removal of V
CC
.
CHIP DISABLE
The chip Disable (pin 1) can be used to power down the IC to conserve power, or for muting, or both. When at a
Logic “0” (0V to 0.8V), the TS34119 is enabled for normal operation. When pin 1 is a Logic ”1” (2V to V
CC
), the IC is
disabled. If pin 1 is open, that is equivalent to Logic “0” although good design proactive dictates that an input should
never be left open. Input impedance at pin 1 is a nominal 90K
. The power supply current (when disabled) is shown
in Figure 15.
Muting, defined as the change in differential gain from normal operation to muted operation, is in excess of 70dB.
The turn-off time the audio output, from the application of the CD signal, is <2uS, and turn on-time is 12 mS-15mS.
Both times are independent of C1, C2, and V
CC
. When the TS34119 is disabled, the voltage at FC1 and FC2 do not
change as they are powered from Vcc. The
outputs, VO1 and VO2, change to high impedance condition, removing
the signal from the speaker. If signals from other sources are to be applied to the outputs (while disabled), they must
be within the range of V
CC
and Ground.
LAYOUT CONSIDERATIONS
Normally a snobbier is not needed at the output of the TS34119, unlike many other audio amplifiers, However, the
PC board layout, stray capacitances, and the manner in which the speaker wires are configured, may dictate
otherwise. Generally, the speaker wires should be twisted tightly, and not more than a few inches in length.
相关PDF资料 |
PDF描述 |
|---|---|
| TS34119CD | Low Power Audio Amplifier |
| TS34119CS | Low Power Audio Amplifier |
| TS34119CA | COAXIAL T CNNCTRS NON-BH BNC AUTO T-CNNCTR F-M-F |
| TS3431AILT | 1.24V programmable shunt voltage reference |
| TS3431CIZ-AP | 1.24V Programmable Shunt Voltage Reference |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TS34119_07 | 制造商:TSC 制造商全称:Taiwan Semiconductor Company, Ltd 功能描述:Low Power Audio Amplifier |
| TS34119CA | 制造商:TSC 制造商全称:Taiwan Semiconductor Company, Ltd 功能描述:Low Power Audio Amplifier |
| TS34119CD | 制造商:TSC 制造商全称:Taiwan Semiconductor Company, Ltd 功能描述:Low Power Audio Amplifier |
| TS34119CD C3 | 制造商:SKMI/Taiwan 功能描述:Audio Amp Speaker 1-CH Mono 0.4W Class-AB 8-Pin DIP Tube |
| TS34119CS | 功能描述:音频放大器 Low Power Audio Amp RoHS:否 制造商:STMicroelectronics 产品:General Purpose Audio Amplifiers 输出类型:Digital 输出功率: THD + 噪声: 工作电源电压:3.3 V 电源电流: 最大功率耗散: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:TQFP-64 封装:Reel |
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