¡ Semiconductor

MSM7705-01/02/03

4/20

PIN AND FUNCTIONAL DESCRIPTIONS

AIN1, AIN2, AIN3, AIN4, GSX1, GSX2, GSX3, GSX4

AIN1, AIN2, AIN3, and AIN4 are the transmit analog inputs for channels 1, 2, 3 and 4

respectively.

GSX1, GSX2, GSX3, and GSX4 are the transmit level adjustments for channels 1, 2, 3 and 4

respectively.

AIN1, AIN2, AIN3, and AIN4 are connected to the inverting inputs for the op-amps. GSX1, GSX2,

GSX3, and GSX4 are connected to the outputs for the op-amps. They are used to adjust levels as

shown below, and are connected to the outputs of the op-amps.

During power saving mode and power down mode, the GSX1, GSX2, GSX3, and GSX4 outputs

are at 0 V.

When these pins are not used, connect AIN1 to GSX1, AIN2 to GSX2, AIN3 to GSX3, and AIN4

to GSX4.

CHn

Analog Input

+

–

AINn

C1n

R1n

R2n

GSXn

CHn Gain

Gain = R2n/R1n £ 10

R1n: Variable

R2n > 20 kW

C1n > 1/(2 ¥ 3.14 ¥ 30 ¥ R1n) (F)

AOUT1, AOUT2, AOUT3, AOUT4

AOUT1, AOUT2, AOUT3, and AOUT4 are the receive filter outputs for channels 1, 2, 3, and 4

respectively.

When the digital signal of +3 dBm0 is input to DIN1, DIN2, DIN3, and DIN4, the output signal

output can drive a load of 600 W or more.

During power saving or power down mode, these outputs are at the voltage level of SG with a

high impedance.