- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄373621 > TDA7336 (意法半導(dǎo)體) STEREO PREAMP+ AMS+ DOLBY B* NOISE REDUCTION PROCESSOR PDF資料下載
參數(shù)資料
| 型號： | TDA7336 |
| 廠商： | 意法半導(dǎo)體 |
| 英文描述： | STEREO PREAMP+ AMS+ DOLBY B* NOISE REDUCTION PROCESSOR |
| 中文描述： | 立體聲前置放大器醫(yī)療輔助隊杜比B *降噪處理器 |
| 文件頁數(shù)： | 8/20頁 |
| 文件大小： | 394K |
| 代理商： | TDA7336 |
AUDIO MUSIC SENSOR (See Figure2)
Aim of this section is to detect interprogram
spaces present on a recordedtape.
Both the blanks (interprogram spaces) and the
programs minimum detectable durations can be
easily set by means of 2 external and inde-
pendent time constants.
Also the minimum detectable input signal level
can be externally adjusted, by a dedicated gain
network.
Main blocksare:
Variablegain limiteramplifier
Signal detector circuitry
Logicblocksableto avoidunproperoperations.
Operations Description (refer to the simplified
schematic of Figure 2).
a)The two channels left and right mean signal
coming from the preamp chain (AC coupled)
are added (current)at the AMSinput and pre-
sented to the limiter amplifier. The limiter am-
plifier gain is internally fixed to 40dB, and it
could be reduced by the R8 external resistor.
The AMSVth threshold is fixed at 1V. The fol-
lowing signal detector comparator informs of
the presence of music signal (High level out)
and avoids the erroneous detection of very
low signal (like noise) as real program.
b)The system moves in blank detection mode
everytime the supply is turned on or, with
power supplied, the AMS On/Off pin (to be
driven by an open collector output) is turned
off (T
1
open). Once this condition has hap-
pened, the capacitor C
15
charges, defining a
minimum reset time, long enough to reset the
Flip-Flops FF
1
and FF
2
and to descharge the
program detector external C
7
capacitor. The
charging current at the AMS SW pin is about
10
μ
A. It follows that the reset time (C
15 x
V
pin7
)/I
C15
is given approximately by 0.122
x
C
15
ns where C
15
is in
μ
F.
c)From now on where the sum input signal (left-
right) amplified by the limiter exceeds the sig-
nal detector threshold (3) the capacitor C
7
is
forced to charge. When the voltage across
this
capacitor
reaches
COMP
1
thresholdvoltage V
th1
(approx.2 V
be
)
FF
1
is set and FF
2
is reset. (4) It follows that
Q
1
is turned on discharging the program de-
tectioncapacitor(C
7
).
the
comparator
d)Always when there is a recorded zone, Q
1
is
on; it becomes off only if a blank section is
reached. When, with a time constant control-
led by the R
9
, C
9
network the voltage at
space detection time pin reaches V
th2
thresh-
old (comparator COMP
2
) a true blank section
is detected and the FF
2
is set. (The minimum
chargingtime is approximatelygiven by:
0.69
x
C
9 x
R
9
[sec]
In this conditionQ
2
is on, forcingthe open col-
lector AMS output to go low, informing the
user that a true blank section has been de-
tected. The state is thenable to start from the
above point c). Figures 3-4 show the signal
behaviour.
The device is able to prevent false interspace de-
tection and the endof thetape. (see Fig. 4).
Note
:
(3): minimumRMS input signal is given by:
V
in
=
AMSVth
1K
+
R
8
101K
+
R
8
0.6
where V
in
is the mean of left and right channels::
V
in
=
V
right
+
V
left
2
(4): the charging current at pin 8 is about 20
μ
A
(half input signal) so program detection time
constantis given by:
C
7
x
2V
be
20
μ
A
=
70
x C
7
[
μ
F]
=
[msec]
It is recommended to insert a resistor (R7) high
enoughto preventfast C7 capacitor discharging.
TDA7336
8/20
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| TDA7338 | STEREO DECODER |
| TDA7338D | STEREO DECODER |
| TDA7339 | 3 BAND DIGITAL CONTROLLED AUDIO PROCESSOR |
| TDA7340G | AUDIO SIGNAL PROCESSOR |
| TDA7340 | AUDIO SIGNAL PROCESSOR |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| TDA7338 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:STEREO DECODER |
| TDA7338_05 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:STEREO DECODER |
| TDA7338D | 功能描述:接口—CODEC Stereo Decoder RoHS:否 制造商:Texas Instruments 類型: 分辨率: 轉(zhuǎn)換速率:48 kSPs 接口類型:I2C ADC 數(shù)量:2 DAC 數(shù)量:4 工作電源電壓:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:DSBGA-81 封裝:Reel |
| TDA7338D013TR | 功能描述:接口—CODEC Stereo Decoder RoHS:否 制造商:Texas Instruments 類型: 分辨率: 轉(zhuǎn)換速率:48 kSPs 接口類型:I2C ADC 數(shù)量:2 DAC 數(shù)量:4 工作電源電壓:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:DSBGA-81 封裝:Reel |
| TDA7339 | 功能描述:音頻 DSP Digital Audio Proc RoHS:否 制造商:Texas Instruments 工作電源電壓: 電源電流: 工作溫度范圍: 安裝風(fēng)格: 封裝 / 箱體: 封裝:Tube |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。