TDA8020HL Datasheet, PDF (11/24 Pages) NXP Semiconductors – Dual smart card interface

Philips Semiconductors
Dual smart card interface
Product specification
TDA8020HL
Deactivation sequence
When the session is completed, the microcontroller resets
bit START/STOP to logic 0 (t10). The circuit then executes
an automatic deactivation sequence (see Fig.5):
• Card reset (RST falls LOW) (t11)
• CLK is stopped (t12)
• I/O falls to 0 V (t13)
• V_CC falls to 0 V with typical 0.14 V/µs slew rate (t14)
• The DC/DC converter is stopped (if both cards are
inactive) and CLK, RST, V_CC and I/O become low
impedance to CGND (t15).
t11 = t10 + T/64; t12 = t11 + T/2; t13 = t11 + T;
t14 = t11 + 3T/2; t15 = t11 + 7T/2.
The deactivation time t_de is the time that V_CC needs to drop
below 0.4 V from START/STOP to logic 0 (t10).
handbook, full pagewidth
START/ STOP
RST
CLK
I/O
VCC
VUP
t _de
t10 t11
t12
t13
t14
t15
Fig.5 Deactivation sequence.
FCE836
2001 Aug 15
11