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參數(shù)資料
| 型號(hào)： | U4080B |
| 英文描述： | Voice-Switched Circuit for Handsfree Operation |
| 中文描述： | 語(yǔ)音電路交換的免提操作 |
| 文件頁(yè)數(shù)： | 7/15頁(yè) |
| 文件大?。?/td> | 169K |
| 代理商： | U4080B |
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U4080B
Preliminary Information
TELEFUNKEN Semiconductors
Rev. A1, 20-May-96
7 (15)
G
T
RTG/R
1
or RG/R
1
0
100
–40
–20
0
20
1000
VR
ACF
= 8 mV
VR
ACF
= 150 mV
R
1
= 30 k
G
T
G
R
G
TR
G
RT
–60
94 7865 e
R
Figure 4.
As can be seen from the truth table, the T-R comparator
dominates. The transmit detector comparator is effective
only in the transmit mode, and the volume control is
effective only in the receive mode. The T-R comparator
is in the transmit position when the transmit signal present
is greater than the receive signal. The transmit detector
comparator then determines whether the transmit signal
is a result of background noise (a relatively constant
signal), or speech, which consists of bursts. If the signal
is due to background noise, the attenuators will be put into
the idle mode ( V
ACF
= 75 mV). If the signal consists of
speech, the attenuators will be switched to the transmit
mode ( V
ACF
= 6.0 mV). For further explanation, please
refer to the transmit detector circuit (Log. amplifiers).
The T-R comparator is in the receive position when there
is sufficient receive signal to overcome the background
noise AND any speech signals. The V
ACF
voltage will
be 150 mV if the volume control is at the maximum
position, i.e. VCI (Pin 24) = V
B
. If VCI
TG will vary in a complementary manner as shown in
figure 5 It can be seen that at the minimum recommended
operating level (VCI = 0.55 V
B
) the gain of the transmit
attenuator is actually greater than that of the receive atten-
uator. The effect of varying VCI is to vary V
ACF
, with
a resulting variation in the gains of the attenuators.
Figure 6 shows the gain variations with V
ACF
.
V
B’,
RG and
0
0.2
0.4
0.6
0.8
VCI
1.0
–40
–20
0
20
–60
G
T
G
R
94 7866 e
G
T
R
Figure 5.
0
40
80
120
V
ACF
(mV)
Figure 6.
160
–40
–20
0
20
–60
R
T
94 7867 e
G
T
R
A 4.7
μ
F capacitor at Pin 25 smooths the transition
between operating modes. This keeps down any “clicks”
in the speaker or transmit signal when the ACF voltage
switches. The gain separation of the two attenuators can
be reduced from the typical 45 dB by connecting a resistor
between Pins 20 and 25. The effect is a reduction of
voltage in the receive mode, but no effect on the transmit
mode voltage.
For example, adding a 12 k
resistor will reduce V
ACF
by approximately 15 mV (to 135 mV), decrease the gain
of the receive attenuator by approximately 5.0 dB, and
increase the gain of the transmit attenuator by a similar
amount. If the circuit requires the receive attenuator gain
to be +6.0 dB in the receive mode, RG must be adjusted
(to 27 k
) to re-establish this value. This change will also
increase the receive attenuator’s gain in the transmit
mode by a similar amount. The resistor at TLI may also
require changing to reset the sensitivity of the transmit
level detector.
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| U4083B-AFP | Low-Power Audio Amplifier for Telephone Applications |
| U4083B-AFPG3 | Low-Power Audio Amplifier for Telephone Applications |
| U4084B-FL | LOW POWER QUAD VOLTAGE COMPARATOR |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| U4082B | 制造商:ATMEL 制造商全稱(chēng):ATMEL Corporation 功能描述:Low-voltage Voice-switched IC for Hands-free Operation |
| U4082B-DEV-BOARD | 功能描述:射頻開(kāi)發(fā)工具 Voice Switched Circuit RoHS:否 制造商:Taiyo Yuden 產(chǎn)品:Wireless Modules 類(lèi)型:Wireless Audio 工具用于評(píng)估:WYSAAVDX7 頻率: 工作電源電壓:3.4 V to 5.5 V |
| U4082B-MFLG | 功能描述:射頻無(wú)線(xiàn)雜項(xiàng) COM.CORDED - VOICE SWITCHED CIRCUIT RoHS:否 制造商:Texas Instruments 工作頻率:112 kHz to 205 kHz 電源電壓-最大:3.6 V 電源電壓-最小:3 V 電源電流:8 mA 最大功率耗散: 工作溫度范圍:- 40 C to + 110 C 封裝 / 箱體:VQFN-48 封裝:Reel |
| U4082B-MFLG3G | 功能描述:射頻無(wú)線(xiàn)雜項(xiàng) COM.CORDED - VOICE SWITCHED CIRCUIT RoHS:否 制造商:Texas Instruments 工作頻率:112 kHz to 205 kHz 電源電壓-最大:3.6 V 電源電壓-最小:3 V 電源電流:8 mA 最大功率耗散: 工作溫度范圍:- 40 C to + 110 C 封裝 / 箱體:VQFN-48 封裝:Reel |
| U4083 | 制造商:TEMIC 制造商全稱(chēng):TEMIC Semiconductors 功能描述:Low-Power Audio Amplifier for Telephone Applications |
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