¡ Semiconductor

MSM7705-01/02/03

17/20

BCLK (kHz)

64

128

256

512

1024

1544

2048

385.6

190.3

92.7

43.8

19.4

11.2

7.2

192.8

95.2

46.3

21.9

9.7

5.6

3.6

77.1

38.1

18.5

8.8

3.9

2.2

1.4

38.6

19.0

9.3

4.4

1.9

1.1

0.7

Rpull (kW)

Choice of Actual Resistor Value

If the calculated value is more than or equal to 100 kW, 100 kW should be employed. +10% of the

calculated value is within a tolerance, thus, for example, the value of 10 kW can be used for the

calculated value of 9.3 kW in the above examples.

Channel Crosstalk

The MSM7705 contains the 4-channel CODEC. The circuit and trace design and pin layout are

made to minimize crosstalk between channels inside the LSI device provided the following

should be taken into consideration.

Transmit side

The GSX1 – AIN2, AIN3, and AIN4 traces should not be kept closer.

The GSX2 – AIN1, AIN3, and AIN4 traces should not be kept closer.

The GSX3 – AIN1, AIN2, and AIN4 traces should not be kept closer.

The GSX4 – AIN1, AIN2, and AIN3 traces should not be kept closer.

AIN1, AIN2, AIN3, and AIN4, which are op-amp inverting input pins, have higher resistance,

therefore proximity of these lines to signal lines of other channels may cause crosstalk.

Receive side

The channel outputs AOUT1, AOUT2, AOUT3, and AOUT4 of the receive side are amplifier

outputs with lower resistance, thus crosstalk due to PCB traces is smaller. Nevertheless, the

PCB traces should not be run closer together and in parallel wherever possible.

Calculation Example for Typical Values