msm7508b Oki Semiconductor, msm7508b Datasheet - Page 4

• Manufacturer Part Number: msm7508b
• Description: Single Rail Codec
• Manufacturer: Oki Semiconductor

¡ Semiconductor
PIN AND FUNCTIONAL DESCRIPTIONS
AIN+, AIN–, GSX
Transmit analog input and transmit level adjustment.
AIN+ is a non-inverting input to the op-amp; AIN– is an inverting input to the op-amp; GSX is
connected to the output of the op-amp and is used to adjust the level, as shown below.
When not using AIN– and AIN+, connect AIN– to GSX and AIN+ to SG. During power saving
and power down modes, the GSX output is in a high impedance state.
AG
Analog signal ground.
AOUT
Analog output.
The output signal amplitude is a maximum of 2.4 V
level (V
The output load resistance is a minimum of 20 kW.
During power saving or power down mode, the output of AOUT is at the voltage level of signal
ground.
DD
/2).
1) Inverting input type
2) Non inverting input type
Analog input
Analog input
R5
C1
C2
R1
R3
R4
R2
GSX
AIN–
AIN+
SG
AIN+
AIN–
GSX
SG
–
+
+
–
PP
above and below the signal ground voltage
R1 : variable
R2 > 20 kW
C1 > 1/(2 ¥ 3.14 ¥ 30 ¥ R1)
Gain = R2/R1 £ 10
R3 > 20 kW
R4 > 20 kW
R5 > 50 kW
C2 > 1/ (2 ¥ 3.14 ¥ 30 ¥ R5)
Gain = 1 + R4 / R3 £ 10
MSM7508B/7509B
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