pbl3853 ETC-unknow, pbl3853 Datasheet - Page 8

• Manufacturer Part Number: pbl3853
• Description: Universal Speech Circuit
• Manufacturer: ETC-unknow

PBL 3853
Detailed Description: Expressions for AC-characteristics
Z
(see fig,15.) elements in the telephone set. R1, R2 and C
Active impedance:
The following expression is derived from fig.12 if 1/ZLoad = 1/Zp + 1/Zline
Figure 12 and the expression above render the following transmitter gain expression:
Figure 12 renders the following expression of the impedance across the circuit:
Figure 12 renders also the following expression of the impedance across R
From figure 13 it is possible to identi
From figure 13 it is possible to identify :
From figure 13 it is possible to identify :
These expressions together by omitting the impedance of the
line Z
set towards the line.The telephone set impedance towards the line is:
I
Figure 12 .
8
Impedance across the circuit
Impedance across R
Transmitter gain
Load
V
Line
Z
L
active
V
R
is the impedance that the telephone sees in the telephone line. Z
0.7
Y
Line
5
R
1
R
1
from the expression, will render the impedance of thetelephone
2
2 fC
R
1
/ /8000 R
R
R
2
12
13
/ /8000
2
Telephone
I
load
Z
0.7
Load
V
V
5
Z
S
1
R
L
=
p
2
R
/ /8000 R
V
2
V
V
1
I
1
/ /8000
Y
Y
S
Z
V
15000 R
load
Telephone line
S
1 1 R
I
1/ R
L
I
10000
1
Load
V
5.8
L
1
R
fy :
5
12
5
R
3
V
/ R
1/ 1 R
/ / R
1
5
Z
Y
1/ Z
line
13
15000 R
4
A
Z
Load
................................................................................................................1
1
...............................................................................................................6
Load
10000
R
= 5.8
12
1
4
R
/ R
/ /15000 R
1 R
4
3
R
V
/ /15000
/ / R
13
L
5
12
4
Z
Load
2
1 R
/ R
1
1
. 1/Zp = 1/R1+2 f C
1 R
Figure 13.
13
3
R
R
12
12
13
Z
10
15
/ R
12
Load
/ R
2
13
..............................................................................7
.............................................................................4
............................................................................5
R
p
13
5
Z
is the impedance formed by the passive
PBL 3853
R
Load
/ R
Z
7
R
Load
10
5
5
:
...............................................................3
2
...........................................................2
(R2 can be omitted if R2 << R1)
C
C *
7
15
*
frequency response
To give receiver flat
R
11
Z
bal
+Line