an12940aa Panasonic Corporation of North America, an12940aa Datasheet - Page 14

• Manufacturer Part Number: an12940aa
• Description: Audio Signal Processing Ic For Notebook Pc
• Manufacturer: Panasonic Corporation of North America

AN12940AA
■ Terminal Equivalent Circuits (continued)
14
Pin No.
53
54
51
50
V
V
51
REG
51
REG
54
(4.5 V)
(4.5 V)
53
Equivalent Circuits
3.5 kΩ
3.5 kΩ
13.1 kΩ
31.7 kΩ
V
160 kΩ
V
160 kΩ
REF
REG
V
(2.25 V)
21.8 kΩ
(4.5 V)
21.8 kΩ
REG
(4.5 V)
SDC00044AEB
50
50
V
With the pin to fix the bias voltage
(the operation point) of the system
which the inner power (V
it becomes 1/2V
noise, it connects a condenser with
the interval of between pin 53 and
GND.
The entry impedance: About 80 kΩ
Modem input:
It is the entry pin to enter a signal
from the modem. With the audio signal
mix amplifier of the following para-
graph, the same signal is entered both
by L-channel and R-channel. Also, it
has the function which is the same as
the PCcard signal entry by pin 4, the
beep signal entry by pin 56
completely.
The entry impedance: About 45 kΩ
The signal detection system
It is the negative feedback pin of the
signal detection system pre-amplifier.
It is possible to adjust in the direction
with the output (pin 50) which
lowers a gain by adding external
resistance between.
The entry impedance: About 0 Ω
The signal detection system
It is the output pin of the signal detection
system pre-amplifier. It is possible to
adjust in the direction which lowers
a gain by adding external resistance
among the negative feedback pins
(pin 51).
The entry impedance: About 0 Ω
pre-amplifier negative feedback pin:
REF
:
pre-amplifier output pin:
Description
REG
(V). To remove
REG
) works,
and Voltage
Corrugation
AC −16 dBV
AC −10 dBV
DC 2.25 V
DC 2.25 V
DC 2.25 V
DC 2.25 V