Technical information

USBUF

8/13

DocID7041 Rev 8

Figure 10. gives the measurement circuit for the analog crosstalk application. In Figure 11.,

the curve shows the effect of the D+ cell on the D-cell. In usual frequency range of analog

signals (up to 100 MHz) the effect on disturbed line is less than -37 db.

Figure 12. Digital crosstalk measurements configuration

Figure 12 shows the measurement circuit used to quantify the crosstalk effect in a classical

digital application.

Figure 13. Digital crosstalk results

Figure 13 shows, with a signal from 0 to 5 V and rise time of few ns, the impact on the

disturbed line is less than 250 mV peak to peak. No data disturbance was noted on the

other line.The measurements performed with falling edges gives an impact within the same

range.

Figure 10. Analog crosstalk

measurements

Figure 11. Typical analog crosstalk

results

Vg

50

Ω

50

Ω

TEST BOARD

UUx

1

10

100

1,000

-100

-80

-60

-40

-20

0

Frequency (MHz)

Analog crosstalk (dB)

D+

D-

+5V

+5V

74HC04

+5V

Square

Pulse

Generator

74HC04

3.3 V

Rp

Ct

Rt

Ct

Rt

D1

Gnd

D2

D4

D3

3.3 V

V