智能卡接口
Description
The ST8024L is a complete low-cost analog interface for asynchronous Class A, B, and C smartcards. It can be placed between the card and the microcontroller with few external components to perform all supply protection and control functions. The ST8024LCDR and ST8024LCTR are compatible with the ST8024 with the exception of Vthextrise/fall value.
Features
■ Designed to be compatible with the NDS conditional access system except
■ ISO 7816, GSM11.11 and EMV 4.2payment systems compatible
■ IC card interface
■ 3 V or 5 V supply for the ST8024L device VDD
■ Three specifically protected half-duplex bi-directional buffered I/O lines to card contacts C4, C7 and C8
■ Step-up converter for VCCgeneration separately powered by a 5 V ± 20% supply VDDPand PGND
■ 1.8 V ± 6.5%, 3 V or 5 V ± 5% regulated card supply voltage VCC with appropriate decoupling has the following capabilities:
–ICC< 80 mA at VDDP= 4.75 to 6.5 V
– Handles current spikes of 40 nA up to 20 MHz
– Controls rise and fall times
– Filtered overload detection at ~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, VDDor VDDPdropout
■ Enhanced ESD protection on card side >6 kV
■ 26 MHz integrated crystal oscillator
■ Built-in debounce on card presence contacts
■ One multiplexed status signal OFF
■ Non-inverted control of RST via pin RSTIN
■ Clock generation for cards up to 20 MHz divided by 1, 2, 4 or 8 through CLKDIV1 and CLKDIV2 signals with synchronous frequency changes
■ Supply supervisor for spike-killing during power-on and power-off and power-on reset threshold fixed internally or externally by a resistor divider
Applications
■ Smartcard readers for set-top boxes
■ IC card readers for banking
■ Identification, pay TV