- 您现在的位置：买卖IC网 > PDF目录378041 > PBL388131SOT (ERICSSON) Voice-switched Speakerphone Circuit with built in loudspeaker amplifier PDF资料下载
参数资料
| 型号： | PBL388131SOT |
| 厂商： | ERICSSON |
| 英文描述： | Voice-switched Speakerphone Circuit with built in loudspeaker amplifier |
| 中文描述： | 语音交换与内置免提扬声器放大器电路 |
| 文件页数： | 10/16页 |
| 文件大小： | 299K |
| 代理商： | PBL388131SOT |
10
PBL 388 13
Figure 21. Speech circuit DC
characteristics.
Figure 18. External power supply options. Line supply with inductor or mains supply.
Figure 17. Power supply in parallel with speech circuit.
Figure 22. Current sharing system.
Figure 20. Typical loudspeaker output
swing.
Loudspeaker amplifier
The loudspeaker amplifier drives
directly a 25 - 50
impedance loudspeaker.
The amplifier is designed to work under a
number of different power supply conditions.
Fig. 17, 18 and 23. The highest output
swing is obtained if pin -C is connected to
ground (- Line) and pin +L is connected to
a stable DC supply. This supply could be
either mains powered or powered from the
telephone line through an inductor. Fig.18.
Current consumption is directly proportio-
nal to the voltage between pins +L and -C.
When using the application according to
figure 17, pin -C is used as the negative
floating supply point for the amplifier. The
output signal of the loudspeaker amplifier
is referred to +L. The reservoir capacitor C
makes it possible for the amplifier to handle
power peaks that are much higher than
would be possible with continuous signal.
The optimal design without using a stable
supply is to balance it against the DC char-
acteristics of the speech circuit that is
working in parallel. This is the main reason
why the power stage is referred to the +line
because otherways there would be the
resistor to ground (-line), see fig. 22. Such
an arrangement is known to be extremely
troublesome in respect of RFI (Radio
Frequency Interference). The single ended
loudspeaker amplifier has an internal gain
regulation that prevents distortion in case
of insufficient line current. The loudspeaker
volume control can be solved in two diffe-
rent ways. One is to use a conventional
potentiometer that will act as an ac voltage
divider at the power amplifier input pin 23.
The second is to control the gain of the
power amplifier by dc. at pin 19. See fig.19.
The controlling element can be a potentio-
meter or a digital control from a
μ
-proces-
sor. See figure 24.
PBL 388 13
LSP 18
+L 20
–C 17
+
+ Line
– Line
GND
16
R
22
E
R
21
DC
Input
23 LSP
in
50 ohm
Connected to speech circuit
pin 2. (see figure 23.)
0.22
μ
16V
100
μ
F
1000
μ
F
16V
RE
0
μ
+
VOL 19
Line
V
I
+L
PBL 388 13
LSP 18
+L 20
–C 17
+
– Line
GND
16
R
22
E
R
21
DC
Input
23 LSP
in
50 ohm
0.22
μ
16V
μ
F
116V
μ
F
0
μ
+
VOL 19
+ Line
1
2
(Alt.1 and 2)
Regulated voltage
from
mains supply
I
+L
+Line
I
L
I
B
I
C
Speech
Circuit
Handsfree
Circuit
Z
≈
0
I
R
-Line
R
Figure 19. Loudspeaker volume control.
2.0
2.4
0.4
1.2
0.8
1.6
0
20
40
60
80
100
I
Line
(mA)
V
0ut (Vp)
V
+
Line
V
R
DC
I
Line
V
F6
PBL 388 13
11
23
16
19
20
18
AC-control
F6
PBL 388 13
50
LOUD
SPEAKER
+
11
23
16
18
20
19
0V
0V
DC-control
0V
+
+line
+line
0V
+
50
LOUD
SPEAKER
0V
相关PDF资料 |
PDF描述 |
|---|---|
| PBL38813 | Voice-switched Speakerphone Circuit with built in loudspeaker amplifier |
| PBL388131N | Voice-switched Speakerphone Circuit with built in loudspeaker amplifier |
| PBL388131SO | Voice-switched Speakerphone Circuit with built in loudspeaker amplifier |
| PBL38814 | Voice - switched 2-channel Circuit with loudspeaker amplifier |
| PBL388141N | Voice - switched 2-channel Circuit with loudspeaker amplifier |
相关代理商/技术参数 |
参数描述 |
|---|---|
| PBL38814 | 制造商:ERICSSON 制造商全称:Ericsson 功能描述:Voice - switched 2-channel Circuit with loudspeaker amplifier |
| PBL388141N | 制造商:ERICSSON 制造商全称:Ericsson 功能描述:Voice - switched 2-channel Circuit with loudspeaker amplifier |
| PBL388141SO | 制造商:ERICSSON 制造商全称:Ericsson 功能描述:Voice - switched 2-channel Circuit with loudspeaker amplifier |
| PBL388141SOT | 制造商:ERICSSON 制造商全称:Ericsson 功能描述:Voice - switched 2-channel Circuit with loudspeaker amplifier |
| PBL3-RP15 | 制造商:Middle Atlantic Products 功能描述: |
发布紧急采购，3分钟左右您将得到回复。