USBUF(2006) View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

USBUF
(Rev.:2006)

EMI filter and line termination for USB upstream ports

STMicroelectronics 

USBUFxxW6

Technical information

Figure 10. Figure 10: Analog crosstalk Figure 11. Typical analog crosstalk

measurements

results

Analog crosstalk (dB)

0

50Ω

Vg

TEST BOARD

UUx

-20

-40

50Ω

-60

-80

-100

1

10

100

Frequency (MHz)

1,000

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

Square

Pulse

Generator

+5V

+5V

74HC04

D+

D1

VG1

Gnd

D-

D2

3.3 V

Rt Rp

Ct

D4

+5V

74HC04

3.3 V

Rt

Ct

D3

β21 VG1

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

digital application.

Figure 13. Digital crosstalk results

VG1

β21VG1

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.

7/11

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