4/7

ST1284-xxA8/T8

FREQUENCY BEHAVIOR OF DATA AND STROBE SIGNALS

TECHNICAL INFORMATION

ST1284

SPECTRUM

ANALYSER

TRACKING

GENERATOR

Vg

Vout

Vin

50

Ω

50

Ω

+5V

Fig. A1: Measurement conditions

1

3

10

30

100

300

1,000

- 30.00

- 25.00

- 20.00

- 15.00

- 10.00

- 5.00

0.00

dB

F (MHz)

1284 - 01

1284 - 02

1284 - 03

Fig. A2: Typical frequency response curve for data

and strobe signals.

In addition to the requirements of termination and EMC compatibility, computing devices are required to be

tested for ESD susceptibility. This test is described in the IEC61000-4-2 and is already in place in Europe.

This test requires that a device tolerates ESD events and remain operational without user intervention.

The ST1284-xxA8/T8 is particularly optimized to perform ESD protection. ESD protection is based on the

use of device which clamps at :

Vouput

V

R I

BR

d

PP

=+

.

This protection function is splitted in 2 stages. As shown in figure A3, the ESD strikes are clamped by the

first stage S1 and then its remaining overvoltage is applied to the second stage through the resistor R.

Such a configuration makes the voltage very low at the output.

ESD PROTECTION

ESD Surge

Vinput

Voutput

Rload

Rg

R

S1

Rd

V

BR

V

BR

V

PP

Device

to be

protected

ST1284-xxA8/T8

Rd

S2

Fig. A3: ST1284 ESD clamping behavior