ST8024

Features:

` IC CARD INTERFACE
` 3 OR 5 V SUPPLY FOR THE IC (VDD AND GND)
` THREE SPECIFICALLY PROTECTED HALF-DUPLEX BI-DIRECTIONAL BUFFERED I/O LINES TO CARD CONTACTS C4, C7 AND C8
` DC/DC CONVERTER FOR VCC GENERATION SEPARATELY POWERED FROM A 5 V ± 20% SUPPLY (VDDP AND PGND)
` 3 OR 5 V ±5% REGULATED CARD SUPPLY VOLTAGE (VCC) WITH APPROPRIATE DECOUPLING HAS THE FOLLOWING CAPABILITIES:
ICC < 80 mA at VDDP = 4 to 6.5 V
HANDLES CURRENT SPIKES OF 40 nAs UP TO 20MHz
CONTROLS RISE AND FALL TIMES
FILTERED OVERLOAD DETECTION AT APPROXIMATELY 120 mA
` THERMAL AND SHORT-CIRCUIT PROTECTION ON ALL CARD CONTACTS
` AUTOMATIC ACTIVATION AND DEACTIVATION SEQUENCES; INITIATED BY SOFTWARE OR BY HARDWARE IN THE EVENT OF A SHORT-CIRCUIT, CARD TAKE-OFF, OVERHEATING, VDD OR VDDP DROP-OUT
` ENHANCED ESD PROTECTION ON CARD SIDE (>6 kV)
` 26 MHz INTEGRATED CRYSTAL OSCILLATOR
` CLOCK GENERATION FOR CARDS UP TO 20 MHz (DIVIDED BY 1, 2, 4 OR 8 THROUGH CLKDIV1 AND CLKDIV2    SIGNALS) WITH SYNCHRONOUS FREQUENCY CHANGES
` NON-INVERTED CONTROL OF RST VIA PIN RSTIN
` ISO 7816, GSM11.11 AND EMV (PAYMENT SYSTEMS) COMPATIBILITY
` SUPPLY SUPERVISOR FOR SPIKE-KILLING DURING POWER-ON AND POWER-OFF AND POWER-ON RESET (THRESHOLD
FIXED INTERNALLY OR EXTERNALLY BY A RESISTOR BRIDGE)
` BUILT-IN DEBOUNCE ON CARD PRESENCE CONTACTS
` ONE MULTIPLEXED STATU SSIGNALOFF

Application

The voltage supervisor is used as Power-on reset and as supply dropout detection during a card session. Supply dropout detection is to ensure that a proper deactivation sequence is followed before the voltage is too low. For the internal voltage supervisor to function, the system microcontroller should operate down to 2.35 V to ensure a proper deactivation sequence. If this is not possible, external resistor values can be chosen to overcome the problem.


Pinout




Specifications

Symbol	Parameter	Min	Max	Unit
VDD, VDDP	Supply Voltage	-0.3	7	V
Vn1	Voltage on pins XTAL1, XTAL2, 5V/3V, RSTIN, AUX2UC, AUX1UC, I/OUC, CLKDIV1, CLKDIV2, PORADJ, CMDVCC, PRES, PRES and OFF	-0.3	VDD + 0.3	V
Vn2	Voltage on card contact pins I/O, RST, AUX1, AUX2 and CLK	-0.3	VCC + 0.3	V
Vn3	Voltage on pins VUP, S1 and S2		9	V
ESD1	MIL-STD-883 class 3 on card contact pins, PRES and PRES (Note 1, 2)	-6	6	kV
ESD2	MIL-STD-883 class 2 on C contact pins and RSTIN (Note 1, 2)	-2	2	kV

Description

The ST8024 is a complete low cost analog interface for asynchronous 3V and 5V smart cards. It can be placed between the card and the microcontroller with few external components to perform all supply protection and control functions. ST8024 is a direct replacement of ST8004.

Main applications are: smartcard readers for Set Top Box, IC card readers for banking, identification, Pay TV.