DocID7041 Rev 8

7/13

USBUF

Technical information

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Figure 8. Remaining voltage at both stages S1 (Vinput) and S2 (Voutput) during ESD

surge

Please note that the USBUF is not only acting for positive ESD surges but also for negative

ones. For these kinds of disturbances it clamps close to ground voltage as shown in Figure

8. (negative surge.

2.4

Latch-up phenomenon

The early aging and destruction of IC’s is often due to latch-up phenomenon which is mainly

induced by dV/dt. Thanks to its structure, the USBUF provides a high immunity to latch-up

phenomenon by smoothing very fast edges.

2.5

Crosstalk behavior

Figure 9. Crosstalk phenomenon

The crosstalk phenomenon is due to the coupling between 2 lines. The coupling factor (

or

point has got an extra value

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 k

Ω).

Vin

Vout

Vin

Vout

Positive surge

Negative surge

Line 1

Line 2

DRIVERS

RECEIVERS

αβ

1

G1

1 2

G2

V+

V

αβ

2

G2

2 1

G1

V+

V