AN2269 datasheet(12/25 Pages) STMICROELECTRONICS

Il numero della parte	AN2269

Spiegazioni elettronici	Using the ST8024 Smartcard Interface

PDF	25 Pages

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Produttore elettronici	STMICROELECTRONICS [STMicroelectronics]

Homepage	http://www.st.com

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12 / 25 page

Emergency Deactivation/Fault Detection

AN2269 - Application Note

12/25

3.3

Fault On Card Removal

If the smart card is pulled out from its socket (PRES goes high or PRES goes low), the

deactivation sequence starts. The OFF pin goes low and the device switches off (see

Figure 9). In order to avoid bouncing on the PRES (or PRES) signal at card insertion or

extraction, as the card is inserted again, OFF goes high just after a period tdebounce (≈ 8ms).

If CMDVcc goes low before this time, after card insertion, the device does not turn itself on

and CMDVcc must wait for tdebounce before going low enough to switch the device on.

Figure 10 on page 12 shows the start of the activation sequence after tdebounce is elapsed.

Figure 9.

Card Extraction

Figure 10.

ST8024 Activation Sequence (after tdebounce)

AN2269 Scheda tecnica(PDF) 12 Page - STMicroelectronics