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MSM7540/7560

¡ Semiconductor

FEDL7540-03

Figure 1 Analog Input/Output Interface

PIN AND FUNCTIONAL DESCRIPTIONS

AIN1, AIN2, GSX1, GSX2

Transmit analog inputs and the output for transmit gain adjustment.

AIN1 (AIN2) connects to the 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 output and the output for receive gain adjustment.

VFRO is the receive filter output. AOUT+ and AOUT– are differential analog signal outputs

AIN1

GSX1

Analog Input

R2

C1

to ENCODER

R1

from DECODER

Analog Output

+ 350 W

* : Side Tone Pass (Gain = R6/RS)

AIN2

GSX2

R4

C2

R3

AOUT–

PWI

R6

RS*

VFRO

R5

–1

AOUT+

–

+

–

+

–

+

Transmit Gain:

= (R2/R1) ¥ (R4/R3)

Receive Gain:

= (R6/R5)