¡ Semiconductor
MSM7704-01/02/03
PIN AND FUNCTIONAL DESCRIPTIONS
AIN1, AIN2, GSX1, GSX2
AIN1 and AIN2 are the transmit analog inputs for channels 1 and 2.
GSX1 and GSX2 are the transmit level adjustments for channels 1 and 2.
AIN1 and AIN2 are inverting inputs for the op-amps. GSX1 and GSX2 are connected to the
outputs of the op-amps and are used to adjust the level, as shown below.
When AIN1 and AIN2 are not used, connect AIN1 to GSX1 and AIN2 to GSX2. During power
saving mode and power down mode, the GSX1 and GSX2 outputs are in high impedance state.
R2
CH1
Analog Input
C1
R1
GSX1
AIN1 –
+
CH1 Gain
Gain = R2/R1
£
10
R1: Variable
R2
>
20 kW
C1
>
1/(2
¥
3.14
¥
30
¥
R1)
R4
CH2
Analog Input
C2
R3
GSX2
AIN2
–
+
CH2 Gain
Gain = R4/R3
£
10
R3: Variable
R4
>
20 kW
C2
>
1/(2
¥
3.14
¥
30
¥
R3)
AOUT1, AOUT2
AOUT1 is the receive analog output for channel 1 and AOUT2 is used for channel 2.
The output signal has an amplitude of 2.0 V
PP
above and below the signal ground voltage (SG
: 1/2 V
DD
). When the digital signal of +3 dBmO is input to DIN1 and DIN2, it can drive a load
of 1.2 kW or more.
During power saving mode, or power down mode, these outputs are at the voltage level of SG
with a high impedance.
V
DD
Power supply for +3 V.
A power supply for an analog circuit in the system to which the device is applied should be used.
A bypass capacitor of 0.1
mF
to 1
mF
with excellent high-frequency characteristics and a capacitor
of 10
mF
to 20
mF
should be connected between this pin and the AG pin if needed.
4/17
OKI [ OKI ELECTRONIC COMPONETS ]
