KBMF01SC6(2004) データシートの表示（PDF） - STMicroelectronics

部品番号

コンポーネント説明

メーカー

KBMF01SC6
(Rev.:2004)

EMI FILTER AND LINE TERMINATION FOR PS/2 MOUSE OR KEYBOARD PORTS

STMicroelectronics 

4. CROSSTALK BEHAVIOR

Figure 7: Crosstalk phenomena

RG1

VG1

RG2

Line 1

Line 2

KBMF

RL1

α1VG1 + β12VG2

VG2

RL2

α2VG2 + β21VG1

DRIVERS

RECEIVERS

The crosstalk phenomena is due to the coupling between 2 lines. The coupling factor ( β12 or β21 )

increases when the gap across lines decreases, this is the reason why we provide crosstalk

measurements for monolithic device to guarantee negligeable crosstalk between the lines. In the example

above the expected signal on load RL2 is α2VG2, in fact the real voltage at this point has got an extra value

β21VG1. This part of the VG1 signal represents the effect of the crosstalk phenomenon of the line 1 on the

line 2. This phenomenon has to be taken into account when the drivers impose fast digital data or high

frequency analog signals in the disturbing line. The perturbed line will be more affected if it works with low

voltage signal or high load impedance (few kΩ).

Figure 8: Analog Crosstalk measurements

configuration

50 Ω TG OUT

Vg

TEST BOARD

RF IN

50 Ω

Figure 9: Typical Analog Crosstalk meas-

urement

crosstalk (dB)

0

-20

-40

-60

-80

-100

-120

1

10

100

F (MHz)

1,000

Figure 8 gives the measurement circuit for the analog crosstalk application. In figure 9, the curve shows

the effect of the Data line on the CLK line. In usual frequency range of analog signals (up to 100MHz) the

effect on disturbed line is less than -37dB.

5/8

Share Link: