AN618 Panasonic Semiconductor, AN618 Datasheet - Page 8

• Manufacturer Part Number: AN618
• Description: Recording and playing amplifier IC for answering telephones
• Manufacturer: Panasonic Semiconductor

1.Setting
(1) Setting the Line Path
1—1 Setting the DC Characteristics
1. Setting the gradient of the I
the line output. Also see 1—2, Setting the AC Characteristics.
AN6175K
8
The AN6175K can be made compatible with local telephone regulations by setting the following characteristics :
How to set the above characteristics is described below.
Referring to Fig.1—1, the resistance of R34 is 27 (standard)as with the current application board.
Also see Fig.1—2.
As shown in Fig.1—2, the resistance of R34 determines the gradient of the I
1. Gradient of the I
2. Degree of shifting of the I
• If R34's resistance is decreased, the gradient decreases.
• If R34's resistance is increased, the gradient increases.
12
L
0
—V
AN6175K
0
L
-V
L
MIC amp.
characteristics
L
characteristics
20
Fig.1—1 Line Output Block Diagram
L
—V
4.2V
3.95V
3.6V
Fig.1—2 I
L
characteristics
37
38
39
V
TRB
TRE
L
CC
—V
2
R33
I
L
L
(mA)
Characteristics
Q3
C38
R34
Higher than
standard
Lower than
standard
Z
L
600
120
V
V
V
L
11.8V
10.6V
8.7V
CC
L
CC
—V
1
1
R34=33
R34=27
R34=20
L
(standard)
characteristics. R34 also affects the gain of
ICs for Telephone