IC card interface

FEATURES

• Single supply voltage interface (3.3 or 5 V environment)

• Low-power sleep mode

• Three specific protected half-duplex bidirectional buffered I/O lines

• VCC regulation (5 V ±5%, ICC <65 mA at VDD = 5 V, with controlled rise and fall times

• Thermal and short-circuit protections with current limitations

• Automatic ISO 7816 activation and deactivation sequences

• Enhanced ESD protections on card side (>6 kV)

• Clock generation for the card up to 12 MHz with synchronous frequency changes

• Clock generation up to 20 MHz (auxiliary clock)

• Synchronous and asynchronous cards (memory and smart cards)

• ISO 7816, GSM11.11 compatibility and EMV (Europay, Mastercard, Visa) compliant

• Step-up converter for VCC generation

• Supply supervisor for spikes elimination and emergency deactivation.

APPLICATIONS

• IC card readers for:

– GSM applications

– banking

– electronic payment

– identification

– Pay TV

– road tolling.

GENERAL DESCRIPTION

The TDA8002 is a complete low-power, analog interface for asynchronous and synchronous cards. It can be placed between the card and the microcontroller. It performs all supply, protection and control functions. It is directly compatible with ISO 7816, GSM11.11 and EMV specifications.

Power supply

The supply pins for the chip are VDDA, VDDD, AGND, DGND1 and DGND2. VDDA and VDDD (i.e. VDD) should be in the range of 3.0 to 6.5 V. All card contacts remain inactive during power-up or power-down. On power-up, the logic is reset by an internal signal. The sequencer is not activated until VDD reaches Vth2 + Vhys2 (see Fig.5). When VDD falls below Vth2, an automatic deactivation sequence of the contacts is performed.

Fault detection

The following fault conditions are monitored by the circuit:

• Short-circuit or high current on VCC

• Removing card during transaction

• VDD dropping

• Overheating.

When one or more of these faults are detected, the circuit pulls the interrupt line OFF to its active LOW state and a deactivation sequence is initiated. In case the card is present the interrupt line OFF is set to HIGH when the microcontroller has reset the CMDVCC line HIGH (after completion of the deactivation sequence). In case the card is not present OFF remains LOW.