msm7718-01 Oki Semiconductor, msm7718-01 Datasheet - Page 4

• Manufacturer Part Number: msm7718-01
• Description: Echo Canceler With Adpcm Codec
• Manufacturer: Oki Semiconductor

¡ Semiconductor
PIN FUNCTIONAL DESCRIPTION
AIN1+, AIN1–, AIN2, GSX1, GSX2
Transmit analog inputs and the outputs for transmit gain adjustment.
AIN1– (AIN2) connects to inverting input of the internal transmit amplifier. AIN1+ connects to non-
inverting input of the internal transmit amplifier. GSX1 (GSX2) connects to the internal transmit
amplifier output. Refer to Fig.1 for gain adjustment.
VFRO, AOUT+, AOUT–, PWI
Receive analog outputs and the output for receive gain adjustment.
VFRO is the receive filter output. AOUT+ and AOUT– are differential analog signal outputs which
can directly drive Z
However, these outputs are in high impedance state during power-down.
Analog Input V1
Differential
Transmit Gain: V
= (R2/R1) ¥ (R4/R3)
Receive Gain: V
= 2 ¥ (R5/R6)
Z
+
–
L
L
=120 nF + 350 W
(= 350 W + 120 nF) or a 1.2 kW load. Refer to Fig.1 for gain adjustment.
C1
C1
O
GSX2
/V
VFRO
/Vi
R1
R1
Figure 1 Analog Interface
C2
V
R2
O
R3
Differential
Analog
Output
R2
R4
R6
R5
AIN1+
AIN1–
GSX1
SGT
AIN2
GSX2
VFRO
PWI
AOUT–
AOUT+
–
+
–
+
–1
–
+
to ENCODER
from DECODER
MSM7718-01
VREF
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