AN618 Panasonic Semiconductor, AN618 Datasheet - Page 19

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

ICs for Telephone
Pin No.
Detailed Pin Descriptions(cont.)
24
25
26
27
28
29
30
SPO2
SPO1
FB
SPI
VSP
RPO
RPI
Symbol
[Loudspeaker amp. input(–)]
Combined R28, R29, C26, and C27 con-
nect to this pin to adjust the gain and the
frequency characteristics of the loud-
speaker amplifier. The loudspeaker
amplifier is added with another gain of 6
dB because of its BTL configuration.
[Loudspeaker amp. input(+)]
The receiver attenuator output signal is
sent from pin 19 to this pin through C28
(coupling capacitor).
[Loudspeaker amp. power input]
The power supply pin for the loudspeaker
amplifiers and other output circuits.
[Receiver preamp. output]
Amplified receiver signals are output
from this pin through C30(coupling
)to Pin9 as the LOG amp.(4)input. Within
the IC, the receiver preamplifier output
also connects to the receiver amplifier for
the HS mode and to the receiver attenua-
tor for the HF mode.
[Receiver preamp. input]
Receiver signals are input from line to
this pin through a high-pass filter consist-
ing of R31, C31, and C32. The filter
removes hum from receiver signals.
[Loudspeaker amp.(2)output]
Pins24 and 25 form a BTL configuration.
The output impedance, Zout=10 .
[Loudspeaker amp.(1)output]
Pins24 and 25 form a BTL configuration.
Connects through R18 and C12 to pin 10
as the LOG amp.(3)input. The output
impedance, Zout=10 .
Description
Rec. preamp.
26
+
–
27
26
30
Equivalent circuit
–
V
+
V
CC
CC
1
25
1
24
40
40
To rec. amp. for
HS mode
To rec. att. for
HF mode
V
CC
AN6175K
1
–
+
–
29
19